[Intel-gfx] [PATCH 03/23] drm/i915: Don't use struct drm_driver.get_scanout_position()
Thomas Zimmermann
tzimmermann at suse.de
Fri Jan 10 12:04:10 UTC 2020
Hi
Am 10.01.20 um 12:59 schrieb Jani Nikula:
> On Fri, 10 Jan 2020, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>> The callback struct drm_driver.get_scanout_position() is deprecated in
>> favor of struct drm_crtc_helper_funcs.get_scanout_position().
>>
>> i915 doesn't use CRTC helpers. The patch duplicates the caller
>> drm_calc_vbltimestamp_from_scanoutpos() for i915, such that the callback
>> function is not needed.
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>> ---
>> drivers/gpu/drm/i915/i915_drv.c | 3 +-
>> drivers/gpu/drm/i915/i915_irq.c | 117 ++++++++++++++++++++++++++++++--
>> drivers/gpu/drm/i915/i915_irq.h | 9 +--
>> 3 files changed, 119 insertions(+), 10 deletions(-)
>
> Not really enthusiastic about the diffstat in a "cleanup" series.
Well, the cleanup is about the content of drm_driver :)
>
> I wonder if you could add a generic helper version of
> drm_calc_vbltimestamp_from_scanoutpos where you pass the
> get_scanout_position function as a parameter. Both
> drm_calc_vbltimestamp_from_scanoutpos and the new
> i915_calc_vbltimestamp_from_scanoutpos would then be fairly thin
> wrappers passing in the relevant get_scanout_position function.
Of course. Will be in v2 of the series.
Best regards
Thomas
>
> This would reduce the almost identical duplication of the function in
> i915.
>
> BR,
> Jani.
>
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index f7385abdd74b..4a0a7fb85c53 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -2769,8 +2769,7 @@ static struct drm_driver driver = {
>> .gem_prime_export = i915_gem_prime_export,
>> .gem_prime_import = i915_gem_prime_import,
>>
>> - .get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos,
>> - .get_scanout_position = i915_get_crtc_scanoutpos,
>> + .get_vblank_timestamp = i915_calc_vbltimestamp_from_scanoutpos,
>>
>> .dumb_create = i915_gem_dumb_create,
>> .dumb_map_offset = i915_gem_dumb_mmap_offset,
>> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>> index afc6aad9bf8c..99d0c3b0feae 100644
>> --- a/drivers/gpu/drm/i915/i915_irq.c
>> +++ b/drivers/gpu/drm/i915/i915_irq.c
>> @@ -52,6 +52,11 @@
>> #include "i915_trace.h"
>> #include "intel_pm.h"
>>
>> +/* Retry timestamp calculation up to 3 times to satisfy
>> + * drm_timestamp_precision before giving up.
>> + */
>> +#define I915_TIMESTAMP_MAXRETRIES 3
>> +
>> /**
>> * DOC: interrupt handling
>> *
>> @@ -762,10 +767,11 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
>> return (position + crtc->scanline_offset) % vtotal;
>> }
>>
>> -bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index,
>> - bool in_vblank_irq, int *vpos, int *hpos,
>> - ktime_t *stime, ktime_t *etime,
>> - const struct drm_display_mode *mode)
>> +static bool i915_get_crtc_scanoutpos(struct drm_device *dev,
>> + unsigned int index, bool in_vblank_irq,
>> + int *vpos, int *hpos,
>> + ktime_t *stime, ktime_t *etime,
>> + const struct drm_display_mode *mode)
>> {
>> struct drm_i915_private *dev_priv = to_i915(dev);
>> struct intel_crtc *crtc = to_intel_crtc(drm_crtc_from_index(dev, index));
>> @@ -879,6 +885,109 @@ bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index,
>> return true;
>> }
>>
>> +bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
>> + unsigned int pipe,
>> + int *max_error,
>> + ktime_t *vblank_time,
>> + bool in_vblank_irq)
>> +{
>> + struct timespec64 ts_etime, ts_vblank_time;
>> + ktime_t stime, etime;
>> + bool vbl_status;
>> + struct drm_crtc *crtc;
>> + const struct drm_display_mode *mode;
>> + struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
>> + int vpos, hpos, i;
>> + int delta_ns, duration_ns;
>> +
>> + crtc = drm_crtc_from_index(dev, pipe);
>> +
>> + if (pipe >= dev->num_crtcs || !crtc) {
>> + DRM_ERROR("Invalid crtc %u\n", pipe);
>> + return false;
>> + }
>> +
>> + if (drm_drv_uses_atomic_modeset(dev))
>> + mode = &vblank->hwmode;
>> + else
>> + mode = &crtc->hwmode;
>> +
>> + /* If mode timing undefined, just return as no-op:
>> + * Happens during initial modesetting of a crtc.
>> + */
>> + if (mode->crtc_clock == 0) {
>> + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
>> + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev));
>> +
>> + return false;
>> + }
>> +
>> + /* Get current scanout position with system timestamp.
>> + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
>> + * if single query takes longer than max_error nanoseconds.
>> + *
>> + * This guarantees a tight bound on maximum error if
>> + * code gets preempted or delayed for some reason.
>> + */
>> + for (i = 0; i < I915_TIMESTAMP_MAXRETRIES; i++) {
>> + /*
>> + * Get vertical and horizontal scanout position vpos, hpos,
>> + * and bounding timestamps stime, etime, pre/post query.
>> + */
>> + vbl_status = i915_get_crtc_scanoutpos(dev, pipe, in_vblank_irq,
>> + &vpos, &hpos, &stime,
>> + &etime, mode);
>> + /* Return as no-op if scanout query unsupported or failed. */
>> + if (!vbl_status) {
>> + DRM_DEBUG("crtc %u : scanoutpos query failed.\n",
>> + pipe);
>> + return false;
>> + }
>> +
>> + /* Compute uncertainty in timestamp of scanout position query. */
>> + duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
>> +
>> + /* Accept result with < max_error nsecs timing uncertainty. */
>> + if (duration_ns <= *max_error)
>> + break;
>> + }
>> +
>> + /* Noisy system timing? */
>> + if (i == I915_TIMESTAMP_MAXRETRIES) {
>> + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
>> + pipe, duration_ns/1000, *max_error/1000, i);
>> + }
>> +
>> + /* Return upper bound of timestamp precision error. */
>> + *max_error = duration_ns;
>> +
>> + /* Convert scanout position into elapsed time at raw_time query
>> + * since start of scanout at first display scanline. delta_ns
>> + * can be negative if start of scanout hasn't happened yet.
>> + */
>> + delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
>> + mode->crtc_clock);
>> +
>> + /* Subtract time delta from raw timestamp to get final
>> + * vblank_time timestamp for end of vblank.
>> + */
>> + *vblank_time = ktime_sub_ns(etime, delta_ns);
>> +
>> + if (!drm_debug_enabled(DRM_UT_VBL))
>> + return true;
>> +
>> + ts_etime = ktime_to_timespec64(etime);
>> + ts_vblank_time = ktime_to_timespec64(*vblank_time);
>> +
>> + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n",
>> + pipe, hpos, vpos,
>> + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000,
>> + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000,
>> + duration_ns / 1000, i);
>> +
>> + return true;
>> +}
>> +
>> int intel_get_crtc_scanline(struct intel_crtc *crtc)
>> {
>> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> diff --git a/drivers/gpu/drm/i915/i915_irq.h b/drivers/gpu/drm/i915/i915_irq.h
>> index 812c47a9c2d6..5f7b133ce721 100644
>> --- a/drivers/gpu/drm/i915/i915_irq.h
>> +++ b/drivers/gpu/drm/i915/i915_irq.h
>> @@ -101,10 +101,11 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
>> void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
>> u8 pipe_mask);
>>
>> -bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
>> - bool in_vblank_irq, int *vpos, int *hpos,
>> - ktime_t *stime, ktime_t *etime,
>> - const struct drm_display_mode *mode);
>> +bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
>> + unsigned int pipe,
>> + int *max_error,
>> + ktime_t *vblank_time,
>> + bool in_vblank_irq);
>>
>> u32 i915_get_vblank_counter(struct drm_crtc *crtc);
>> u32 g4x_get_vblank_counter(struct drm_crtc *crtc);
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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