/* * drm_irq.c IRQ and vblank support * * \author Rickard E. (Rik) Faith <[email protected]> * \author Gareth Hughes <[email protected]> * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include <linux/export.h> #include <linux/kthread.h> #include <linux/moduleparam.h> #include <drm/drm_crtc.h> #include <drm/drm_drv.h> #include <drm/drm_framebuffer.h> #include <drm/drm_managed.h> #include <drm/drm_modeset_helper_vtables.h> #include <drm/drm_print.h> #include <drm/drm_vblank.h> #include "drm_internal.h" #include "drm_trace.h" /** * DOC: vblank handling * * From the computer's perspective, every time the monitor displays * a new frame the scanout engine has "scanned out" the display image * from top to bottom, one row of pixels at a time. The current row * of pixels is referred to as the current scanline. * * In addition to the display's visible area, there's usually a couple of * extra scanlines which aren't actually displayed on the screen. * These extra scanlines don't contain image data and are occasionally used * for features like audio and infoframes. The region made up of these * scanlines is referred to as the vertical blanking region, or vblank for * short. * * For historical reference, the vertical blanking period was designed to * give the electron gun (on CRTs) enough time to move back to the top of * the screen to start scanning out the next frame. Similar for horizontal * blanking periods. They were designed to give the electron gun enough * time to move back to the other side of the screen to start scanning the * next scanline. * * :: * * * physical → ⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ * top of | | * display | | * | New frame | * | | * |↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓| * |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| ← Scanline, * |↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓| updates the * | | frame as it * | | travels down * | | ("scan out") * | Old frame | * | | * | | * | | * | | physical * | | bottom of * vertical |⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽| ← display * blanking ┆xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx┆ * region → ┆xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx┆ * ┆xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx┆ * start of → ⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽ * new frame * * "Physical top of display" is the reference point for the high-precision/ * corrected timestamp. * * On a lot of display hardware, programming needs to take effect during the * vertical blanking period so that settings like gamma, the image buffer * buffer to be scanned out, etc. can safely be changed without showing * any visual artifacts on the screen. In some unforgiving hardware, some of * this programming has to both start and end in the same vblank. To help * with the timing of the hardware programming, an interrupt is usually * available to notify the driver when it can start the updating of registers. * The interrupt is in this context named the vblank interrupt. * * The vblank interrupt may be fired at different points depending on the * hardware. Some hardware implementations will fire the interrupt when the * new frame start, other implementations will fire the interrupt at different * points in time. * * Vertical blanking plays a major role in graphics rendering. To achieve * tear-free display, users must synchronize page flips and/or rendering to * vertical blanking. The DRM API offers ioctls to perform page flips * synchronized to vertical blanking and wait for vertical blanking. * * The DRM core handles most of the vertical blanking management logic, which * involves filtering out spurious interrupts, keeping race-free blanking * counters, coping with counter wrap-around and resets and keeping use counts. * It relies on the driver to generate vertical blanking interrupts and * optionally provide a hardware vertical blanking counter. * * Drivers must initialize the vertical blanking handling core with a call to * drm_vblank_init(). Minimally, a driver needs to implement * &drm_crtc_funcs.enable_vblank and &drm_crtc_funcs.disable_vblank plus call * drm_crtc_handle_vblank() in its vblank interrupt handler for working vblank * support. * * Vertical blanking interrupts can be enabled by the DRM core or by drivers * themselves (for instance to handle page flipping operations). The DRM core * maintains a vertical blanking use count to ensure that the interrupts are not * disabled while a user still needs them. To increment the use count, drivers * call drm_crtc_vblank_get() and release the vblank reference again with * drm_crtc_vblank_put(). In between these two calls vblank interrupts are * guaranteed to be enabled. * * On many hardware disabling the vblank interrupt cannot be done in a race-free * manner, see &drm_vblank_crtc_config.disable_immediate and * &drm_driver.max_vblank_count. In that case the vblank core only disables the * vblanks after a timer has expired, which can be configured through the * ``vblankoffdelay`` module parameter. * * Drivers for hardware without support for vertical-blanking interrupts * must not call drm_vblank_init(). For such drivers, atomic helpers will * automatically generate fake vblank events as part of the display update. * This functionality also can be controlled by the driver by enabling and * disabling struct drm_crtc_state.no_vblank. */ /* Retry timestamp calculation up to 3 times to satisfy * drm_timestamp_precision before giving up. */ #define DRM_TIMESTAMP_MAXRETRIES … /* Threshold in nanoseconds for detection of redundant * vblank irq in drm_handle_vblank(). 1 msec should be ok. */ #define DRM_REDUNDANT_VBLIRQ_THRESH_NS … static bool drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, ktime_t *tvblank, bool in_vblank_irq); static unsigned int drm_timestamp_precision = …; /* Default to 20 usecs. */ static int drm_vblank_offdelay = …; /* Default to 5000 msecs. */ module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600); module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600); MODULE_PARM_DESC(…) …; MODULE_PARM_DESC(…) …; static struct drm_vblank_crtc * drm_vblank_crtc(struct drm_device *dev, unsigned int pipe) { … } struct drm_vblank_crtc * drm_crtc_vblank_crtc(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); static void store_vblank(struct drm_device *dev, unsigned int pipe, u32 vblank_count_inc, ktime_t t_vblank, u32 last) { … } static u32 drm_max_vblank_count(struct drm_device *dev, unsigned int pipe) { … } /* * "No hw counter" fallback implementation of .get_vblank_counter() hook, * if there is no usable hardware frame counter available. */ static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe) { … } static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe) { … } /* * Reset the stored timestamp for the current vblank count to correspond * to the last vblank occurred. * * Only to be called from drm_crtc_vblank_on(). * * Note: caller must hold &drm_device.vbl_lock since this reads & writes * device vblank fields. */ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe) { … } /* * Call back into the driver to update the appropriate vblank counter * (specified by @pipe). Deal with wraparound, if it occurred, and * update the last read value so we can deal with wraparound on the next * call if necessary. * * Only necessary when going from off->on, to account for frames we * didn't get an interrupt for. * * Note: caller must hold &drm_device.vbl_lock since this reads & writes * device vblank fields. */ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, bool in_vblank_irq) { … } u64 drm_vblank_count(struct drm_device *dev, unsigned int pipe) { … } /** * drm_crtc_accurate_vblank_count - retrieve the master vblank counter * @crtc: which counter to retrieve * * This function is similar to drm_crtc_vblank_count() but this function * interpolates to handle a race with vblank interrupts using the high precision * timestamping support. * * This is mostly useful for hardware that can obtain the scanout position, but * doesn't have a hardware frame counter. */ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); static void __disable_vblank(struct drm_device *dev, unsigned int pipe) { … } /* * Disable vblank irq's on crtc, make sure that last vblank count * of hardware and corresponding consistent software vblank counter * are preserved, even if there are any spurious vblank irq's after * disable. */ void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe) { … } static void vblank_disable_fn(struct timer_list *t) { … } static void drm_vblank_init_release(struct drm_device *dev, void *ptr) { … } /** * drm_vblank_init - initialize vblank support * @dev: DRM device * @num_crtcs: number of CRTCs supported by @dev * * This function initializes vblank support for @num_crtcs display pipelines. * Cleanup is handled automatically through a cleanup function added with * drmm_add_action_or_reset(). * * Returns: * Zero on success or a negative error code on failure. */ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs) { … } EXPORT_SYMBOL(…); /** * drm_dev_has_vblank - test if vblanking has been initialized for * a device * @dev: the device * * Drivers may call this function to test if vblank support is * initialized for a device. For most hardware this means that vblanking * can also be enabled. * * Atomic helpers use this function to initialize * &drm_crtc_state.no_vblank. See also drm_atomic_helper_check_modeset(). * * Returns: * True if vblanking has been initialized for the given device, false * otherwise. */ bool drm_dev_has_vblank(const struct drm_device *dev) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_waitqueue - get vblank waitqueue for the CRTC * @crtc: which CRTC's vblank waitqueue to retrieve * * This function returns a pointer to the vblank waitqueue for the CRTC. * Drivers can use this to implement vblank waits using wait_event() and related * functions. */ wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_calc_timestamping_constants - calculate vblank timestamp constants * @crtc: drm_crtc whose timestamp constants should be updated. * @mode: display mode containing the scanout timings * * Calculate and store various constants which are later needed by vblank and * swap-completion timestamping, e.g, by * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from * CRTC's true scanout timing, so they take things like panel scaling or * other adjustments into account. */ void drm_calc_timestamping_constants(struct drm_crtc *crtc, const struct drm_display_mode *mode) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank * timestamp helper * @crtc: CRTC whose vblank timestamp to retrieve * @max_error: Desired maximum allowable error in timestamps (nanosecs) * On return contains true maximum error of timestamp * @vblank_time: Pointer to time which should receive the timestamp * @in_vblank_irq: * True when called from drm_crtc_handle_vblank(). Some drivers * need to apply some workarounds for gpu-specific vblank irq quirks * if flag is set. * @get_scanout_position: * Callback function to retrieve the scanout position. See * @struct drm_crtc_helper_funcs.get_scanout_position. * * Implements calculation of exact vblank timestamps from given drm_display_mode * timings and current video scanout position of a CRTC. * * The current implementation only handles standard video modes. For double scan * and interlaced modes the driver is supposed to adjust the hardware mode * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to * match the scanout position reported. * * Note that atomic drivers must call drm_calc_timestamping_constants() before * enabling a CRTC. The atomic helpers already take care of that in * drm_atomic_helper_calc_timestamping_constants(). * * Returns: * Returns true on success, and false on failure, i.e. when no accurate * timestamp could be acquired. */ bool drm_crtc_vblank_helper_get_vblank_timestamp_internal( struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, bool in_vblank_irq, drm_vblank_get_scanout_position_func get_scanout_position) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp * helper * @crtc: CRTC whose vblank timestamp to retrieve * @max_error: Desired maximum allowable error in timestamps (nanosecs) * On return contains true maximum error of timestamp * @vblank_time: Pointer to time which should receive the timestamp * @in_vblank_irq: * True when called from drm_crtc_handle_vblank(). Some drivers * need to apply some workarounds for gpu-specific vblank irq quirks * if flag is set. * * Implements calculation of exact vblank timestamps from given drm_display_mode * timings and current video scanout position of a CRTC. This can be directly * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a kms * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. * * The current implementation only handles standard video modes. For double scan * and interlaced modes the driver is supposed to adjust the hardware mode * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to * match the scanout position reported. * * Note that atomic drivers must call drm_calc_timestamping_constants() before * enabling a CRTC. The atomic helpers already take care of that in * drm_atomic_helper_calc_timestamping_constants(). * * Returns: * Returns true on success, and false on failure, i.e. when no accurate * timestamp could be acquired. */ bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, bool in_vblank_irq) { … } EXPORT_SYMBOL(…); /** * drm_crtc_get_last_vbltimestamp - retrieve raw timestamp for the most * recent vblank interval * @crtc: CRTC whose vblank timestamp to retrieve * @tvblank: Pointer to target time which should receive the timestamp * @in_vblank_irq: * True when called from drm_crtc_handle_vblank(). Some drivers * need to apply some workarounds for gpu-specific vblank irq quirks * if flag is set. * * Fetches the system timestamp corresponding to the time of the most recent * vblank interval on specified CRTC. May call into kms-driver to * compute the timestamp with a high-precision GPU specific method. * * Returns zero if timestamp originates from uncorrected do_gettimeofday() * call, i.e., it isn't very precisely locked to the true vblank. * * Returns: * True if timestamp is considered to be very precise, false otherwise. */ static bool drm_crtc_get_last_vbltimestamp(struct drm_crtc *crtc, ktime_t *tvblank, bool in_vblank_irq) { … } static bool drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, ktime_t *tvblank, bool in_vblank_irq) { … } /** * drm_crtc_vblank_count - retrieve "cooked" vblank counter value * @crtc: which counter to retrieve * * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. Note that this timer isn't correct against a racing * vblank interrupt (since it only reports the software vblank counter), see * drm_crtc_accurate_vblank_count() for such use-cases. * * Note that for a given vblank counter value drm_crtc_handle_vblank() * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() * provide a barrier: Any writes done before calling * drm_crtc_handle_vblank() will be visible to callers of the later * functions, if the vblank count is the same or a later one. * * See also &drm_vblank_crtc.count. * * Returns: * The software vblank counter. */ u64 drm_crtc_vblank_count(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the * system timestamp corresponding to that vblank counter value. * @dev: DRM device * @pipe: index of CRTC whose counter to retrieve * @vblanktime: Pointer to ktime_t to receive the vblank timestamp. * * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. Returns corresponding system timestamp of the time * of the vblank interval that corresponds to the current vblank counter value. * * This is the legacy version of drm_crtc_vblank_count_and_time(). */ static u64 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, ktime_t *vblanktime) { … } /** * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value * and the system timestamp corresponding to that vblank counter value * @crtc: which counter to retrieve * @vblanktime: Pointer to time to receive the vblank timestamp. * * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. Returns corresponding system timestamp of the time * of the vblank interval that corresponds to the current vblank counter value. * * Note that for a given vblank counter value drm_crtc_handle_vblank() * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() * provide a barrier: Any writes done before calling * drm_crtc_handle_vblank() will be visible to callers of the later * functions, if the vblank count is the same or a later one. * * See also &drm_vblank_crtc.count. */ u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, ktime_t *vblanktime) { … } EXPORT_SYMBOL(…); /** * drm_crtc_next_vblank_start - calculate the time of the next vblank * @crtc: the crtc for which to calculate next vblank time * @vblanktime: pointer to time to receive the next vblank timestamp. * * Calculate the expected time of the start of the next vblank period, * based on time of previous vblank and frame duration */ int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime) { … } EXPORT_SYMBOL(…); static void send_vblank_event(struct drm_device *dev, struct drm_pending_vblank_event *e, u64 seq, ktime_t now) { … } /** * drm_crtc_arm_vblank_event - arm vblank event after pageflip * @crtc: the source CRTC of the vblank event * @e: the event to send * * A lot of drivers need to generate vblank events for the very next vblank * interrupt. For example when the page flip interrupt happens when the page * flip gets armed, but not when it actually executes within the next vblank * period. This helper function implements exactly the required vblank arming * behaviour. * * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an * atomic commit must ensure that the next vblank happens at exactly the same * time as the atomic commit is committed to the hardware. This function itself * does **not** protect against the next vblank interrupt racing with either this * function call or the atomic commit operation. A possible sequence could be: * * 1. Driver commits new hardware state into vblank-synchronized registers. * 2. A vblank happens, committing the hardware state. Also the corresponding * vblank interrupt is fired off and fully processed by the interrupt * handler. * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event(). * 4. The event is only send out for the next vblank, which is wrong. * * An equivalent race can happen when the driver calls * drm_crtc_arm_vblank_event() before writing out the new hardware state. * * The only way to make this work safely is to prevent the vblank from firing * (and the hardware from committing anything else) until the entire atomic * commit sequence has run to completion. If the hardware does not have such a * feature (e.g. using a "go" bit), then it is unsafe to use this functions. * Instead drivers need to manually send out the event from their interrupt * handler by calling drm_crtc_send_vblank_event() and make sure that there's no * possible race with the hardware committing the atomic update. * * Caller must hold a vblank reference for the event @e acquired by a * drm_crtc_vblank_get(), which will be dropped when the next vblank arrives. */ void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, struct drm_pending_vblank_event *e) { … } EXPORT_SYMBOL(…); /** * drm_crtc_send_vblank_event - helper to send vblank event after pageflip * @crtc: the source CRTC of the vblank event * @e: the event to send * * Updates sequence # and timestamp on event for the most recently processed * vblank, and sends it to userspace. Caller must hold event lock. * * See drm_crtc_arm_vblank_event() for a helper which can be used in certain * situation, especially to send out events for atomic commit operations. */ void drm_crtc_send_vblank_event(struct drm_crtc *crtc, struct drm_pending_vblank_event *e) { … } EXPORT_SYMBOL(…); static int __enable_vblank(struct drm_device *dev, unsigned int pipe) { … } static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) { … } int drm_vblank_get(struct drm_device *dev, unsigned int pipe) { … } /** * drm_crtc_vblank_get - get a reference count on vblank events * @crtc: which CRTC to own * * Acquire a reference count on vblank events to avoid having them disabled * while in use. * * Returns: * Zero on success or a negative error code on failure. */ int drm_crtc_vblank_get(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); void drm_vblank_put(struct drm_device *dev, unsigned int pipe) { … } /** * drm_crtc_vblank_put - give up ownership of vblank events * @crtc: which counter to give up * * Release ownership of a given vblank counter, turning off interrupts * if possible. Disable interrupts after &drm_vblank_crtc_config.offdelay_ms * milliseconds. */ void drm_crtc_vblank_put(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_wait_one_vblank - wait for one vblank * @dev: DRM device * @pipe: CRTC index * * This waits for one vblank to pass on @pipe, using the irq driver interfaces. * It is a failure to call this when the vblank irq for @pipe is disabled, e.g. * due to lack of driver support or because the crtc is off. * * This is the legacy version of drm_crtc_wait_one_vblank(). */ void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe) { … } EXPORT_SYMBOL(…); /** * drm_crtc_wait_one_vblank - wait for one vblank * @crtc: DRM crtc * * This waits for one vblank to pass on @crtc, using the irq driver interfaces. * It is a failure to call this when the vblank irq for @crtc is disabled, e.g. * due to lack of driver support or because the crtc is off. */ void drm_crtc_wait_one_vblank(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_off - disable vblank events on a CRTC * @crtc: CRTC in question * * Drivers can use this function to shut down the vblank interrupt handling when * disabling a crtc. This function ensures that the latest vblank frame count is * stored so that drm_vblank_on can restore it again. * * Drivers must use this function when the hardware vblank counter can get * reset, e.g. when suspending or disabling the @crtc in general. */ void drm_crtc_vblank_off(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_reset - reset vblank state to off on a CRTC * @crtc: CRTC in question * * Drivers can use this function to reset the vblank state to off at load time. * Drivers should use this together with the drm_crtc_vblank_off() and * drm_crtc_vblank_on() functions. The difference compared to * drm_crtc_vblank_off() is that this function doesn't save the vblank counter * and hence doesn't need to call any driver hooks. * * This is useful for recovering driver state e.g. on driver load, or on resume. */ void drm_crtc_vblank_reset(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /** * drm_crtc_set_max_vblank_count - configure the hw max vblank counter value * @crtc: CRTC in question * @max_vblank_count: max hardware vblank counter value * * Update the maximum hardware vblank counter value for @crtc * at runtime. Useful for hardware where the operation of the * hardware vblank counter depends on the currently active * display configuration. * * For example, if the hardware vblank counter does not work * when a specific connector is active the maximum can be set * to zero. And when that specific connector isn't active the * maximum can again be set to the appropriate non-zero value. * * If used, must be called before drm_vblank_on(). */ void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, u32 max_vblank_count) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_on_config - enable vblank events on a CRTC with custom * configuration options * @crtc: CRTC in question * @config: Vblank configuration value * * See drm_crtc_vblank_on(). In addition, this function allows you to provide a * custom vblank configuration for a given CRTC. * * Note that @config is copied, the pointer does not need to stay valid beyond * this function call. For details of the parameters see * struct drm_vblank_crtc_config. */ void drm_crtc_vblank_on_config(struct drm_crtc *crtc, const struct drm_vblank_crtc_config *config) { … } EXPORT_SYMBOL(…); /** * drm_crtc_vblank_on - enable vblank events on a CRTC * @crtc: CRTC in question * * This functions restores the vblank interrupt state captured with * drm_crtc_vblank_off() again and is generally called when enabling @crtc. Note * that calls to drm_crtc_vblank_on() and drm_crtc_vblank_off() can be * unbalanced and so can also be unconditionally called in driver load code to * reflect the current hardware state of the crtc. * * Note that unlike in drm_crtc_vblank_on_config(), default values are used. */ void drm_crtc_vblank_on(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); static void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) { … } /** * drm_crtc_vblank_restore - estimate missed vblanks and update vblank count. * @crtc: CRTC in question * * Power manamement features can cause frame counter resets between vblank * disable and enable. Drivers can use this function in their * &drm_crtc_funcs.enable_vblank implementation to estimate missed vblanks since * the last &drm_crtc_funcs.disable_vblank using timestamps and update the * vblank counter. * * Note that drivers must have race-free high-precision timestamping support, * i.e. &drm_crtc_funcs.get_vblank_timestamp must be hooked up and * &drm_vblank_crtc_config.disable_immediate must be set to indicate the * time-stamping functions are race-free against vblank hardware counter * increments. */ void drm_crtc_vblank_restore(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe, u64 req_seq, union drm_wait_vblank *vblwait, struct drm_file *file_priv) { … } static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait) { … } /* * Widen a 32-bit param to 64-bits. * * \param narrow 32-bit value (missing upper 32 bits) * \param near 64-bit value that should be 'close' to near * * This function returns a 64-bit value using the lower 32-bits from * 'narrow' and constructing the upper 32-bits so that the result is * as close as possible to 'near'. */ static u64 widen_32_to_64(u32 narrow, u64 near) { … } static void drm_wait_vblank_reply(struct drm_device *dev, unsigned int pipe, struct drm_wait_vblank_reply *reply) { … } static bool drm_wait_vblank_supported(struct drm_device *dev) { … } int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { … } static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) { … } /** * drm_handle_vblank - handle a vblank event * @dev: DRM device * @pipe: index of CRTC where this event occurred * * Drivers should call this routine in their vblank interrupt handlers to * update the vblank counter and send any signals that may be pending. * * This is the legacy version of drm_crtc_handle_vblank(). */ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { … } EXPORT_SYMBOL(…); /** * drm_crtc_handle_vblank - handle a vblank event * @crtc: where this event occurred * * Drivers should call this routine in their vblank interrupt handlers to * update the vblank counter and send any signals that may be pending. * * This is the native KMS version of drm_handle_vblank(). * * Note that for a given vblank counter value drm_crtc_handle_vblank() * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() * provide a barrier: Any writes done before calling * drm_crtc_handle_vblank() will be visible to callers of the later * functions, if the vblank count is the same or a later one. * * See also &drm_vblank_crtc.count. * * Returns: * True if the event was successfully handled, false on failure. */ bool drm_crtc_handle_vblank(struct drm_crtc *crtc) { … } EXPORT_SYMBOL(…); /* * Get crtc VBLANK count. * * \param dev DRM device * \param data user argument, pointing to a drm_crtc_get_sequence structure. * \param file_priv drm file private for the user's open file descriptor */ int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { … } /* * Queue a event for VBLANK sequence * * \param dev DRM device * \param data user argument, pointing to a drm_crtc_queue_sequence structure. * \param file_priv drm file private for the user's open file descriptor */ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { … }
Codebase Browser
linux