[PATCH v8 3/8] drm/i915: Add checks specific to async flips
Karthik B S
karthik.b.s at intel.com
Wed Sep 16 12:44:21 UTC 2020
On 9/15/2020 7:33 PM, Ville Syrjälä wrote:
> On Mon, Sep 14, 2020 at 11:26:28AM +0530, Karthik B S wrote:
>> If flip is requested on any other plane, reject it.
>>
>> Make sure there is no change in fbc, offset and framebuffer modifiers
>> when async flip is requested.
>>
>> If any of these are modified, reject async flip.
>>
>> v2: -Replace DRM_ERROR (Paulo)
>> -Add check for changes in OFFSET, FBC, RC(Paulo)
>>
>> v3: -Removed TODO as benchmarking tests have been run now.
>>
>> v4: -Added more state checks for async flip (Ville)
>> -Moved intel_atomic_check_async to the end of intel_atomic_check
>> as the plane checks needs to pass before this. (Ville)
>> -Removed crtc_state->enable_fbc check. (Ville)
>> -Set the I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP flag for async
>> flip case as scanline counter is not reliable here.
>>
>> v5: -Fix typo and other check patch errors seen in CI
>> in 'intel_atomic_check_async' function.
>>
>> v6: -Don't call intel_atomic_check_async multiple times. (Ville)
>> -Remove the check for n_planes in intel_atomic_check_async
>> -Added documentation for async flips. (Paulo)
>>
>> v7: -Replace 'intel_plane' with 'plane'. (Ville)
>> -Replace all uapi.foo as hw.foo. (Ville)
>> -Do not use intel_wm_need_update function. (Ville)
>> -Add destination coordinate check. (Ville)
>> -Do not allow async flip with linear buffer
>> on older hw as it has issues with this. (Ville)
>> -Remove break after intel_atomic_check_async. (Ville)
>>
>> v8: -Rebased.
>>
>> Signed-off-by: Karthik B S <karthik.b.s at intel.com>
>> Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
>> ---
>> drivers/gpu/drm/i915/display/intel_display.c | 143 +++++++++++++++++++
>> 1 file changed, 143 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>> index 2902fefd217f..a0c17d94daf3 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -14876,6 +14876,142 @@ static bool intel_cpu_transcoders_need_modeset(struct intel_atomic_state *state,
>> return false;
>> }
>>
>> +/**
>> + * DOC: asynchronous flip implementation
>> + *
>> + * Asynchronous page flip is the implementation for the DRM_MODE_PAGE_FLIP_ASYNC
>> + * flag. Currently async flip is only supported via the drmModePageFlip IOCTL.
>> + * Correspondingly, support is currently added for primary plane only.
>> + *
>> + * Async flip can only change the plane surface address, so anything else
>> + * changing is rejected from the intel_atomic_check_async() function.
>> + * Once this check is cleared, flip done interrupt is enabled using
>> + * the skl_enable_flip_done() function.
>> + *
>> + * As soon as the surface address register is written, flip done interrupt is
>> + * generated and the requested events are sent to the usersapce in the interrupt
>> + * handler itself. The timestamp and sequence sent during the flip done event
>> + * correspond to the last vblank and have no relation to the actual time when
>> + * the flip done event was sent.
>> + */
>> +
>> +static int intel_atomic_check_async(struct intel_atomic_state *state)
>> +{
>> + struct drm_i915_private *dev_priv = to_i915(state->base.dev);
>> + struct intel_crtc_state *old_crtc_state, *new_crtc_state;
>> + struct intel_plane_state *new_plane_state, *old_plane_state;
>> + struct intel_crtc *crtc;
>> + struct intel_plane *plane;
>> + int i;
>> +
>> + for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>> + new_crtc_state, i) {
>> + if (needs_modeset(new_crtc_state)) {
>> + DRM_DEBUG_KMS("Modeset Required. Async flip not supported\n");
>
> Per-device debugs pls. drm_dbg_kms() etc.
>
Thanks for the review.
Sure, I'll update this.
>> + return -EINVAL;
>> + }
>> +
>> + if (!new_crtc_state->hw.active) {
>> + DRM_DEBUG_KMS("CRTC inactive\n");
>> + return -EINVAL;
>> + }
>> + if (old_crtc_state->active_planes != new_crtc_state->active_planes) {
>> + DRM_DEBUG_KMS("Active planes cannot be changed during async flip\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + for_each_oldnew_intel_plane_in_state(state, plane, old_plane_state,
>> + new_plane_state, i) {
>> + /*TODO: Async flip is only supported through the page flip IOCTL
>
> Comment formatting is wrong.
>
I'll fix this.
>> + * as of now. So support currently added for primary plane only.
>> + * Support for other planes should be added when async flip is
>> + * enabled in the atomic IOCTL path.
>
> Obviously only for hw that actually supports it. Which I think
> means vlv/chv and icl+.
>
Sure, I'll add this in the comment.
>> + */
>> + if (plane->id != PLANE_PRIMARY)
>> + return -EINVAL;
>> +
>> + /*FIXME: This check is kept generic for all gen <= 10 platforms.
>
> More bad formatting.
>
I'll fix this.
>> + * Need to verify this for all gen9 and gen10 platforms to enable
>> + * this selectively if required.
>> + */
>> + if (new_plane_state->hw.fb->modifier == DRM_FORMAT_MOD_LINEAR &&
>> + INTEL_GEN(dev_priv) <= 10) {
>
> I would drop the gen check for the time being. Much easier for
> bisection if we don't enable random features for random platforms in
> the initial enabling patch.
>
Sure, I'll remove the gen check.
> Hmm. We're also missing a check for CCS. CCS does not support async
> flips iirc. So I recommand only explicitly allowing X/Y/Yf tile here
> (assuming all those are supposed to work), reject everything else.
>
Sure, I'll modify the check accordingly.
>> + DRM_DEBUG_KMS("Linear memory does not support async flips on gen <= 10\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->color_plane[0].x !=
>> + new_plane_state->color_plane[0].x ||
>> + old_plane_state->color_plane[0].y !=
>> + new_plane_state->color_plane[0].y) {
>> + DRM_DEBUG_KMS("Offsets cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.fb->modifier !=
>> + new_plane_state->hw.fb->modifier) {
>> + DRM_DEBUG_KMS("Framebuffer modifiers cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.fb->format !=
>> + new_plane_state->hw.fb->format) {
>> + DRM_DEBUG_KMS("Framebuffer format cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.rotation !=
>> + new_plane_state->hw.rotation) {
>> + DRM_DEBUG_KMS("Rotation cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.fb->width !=
>> + new_plane_state->hw.fb->width ||
>> + old_plane_state->hw.fb->height !=
>> + new_plane_state->hw.fb->height) {
>
> FB size is irrelevant. This check can be dropped.
>
Sure, I'll remove this.
> But stride will need to be checked. Looks like that one is missing.
> Though we should check plane_state->color_plane[0].stride instead
> of the original fb stride, since the former is what we actually program
> into the hw.
>
Sure, I'll update accordingly.
>> + DRM_DEBUG_KMS("Framebuffer dimensions cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->uapi.src_w != new_plane_state->uapi.src_w ||
>> + old_plane_state->uapi.src_h != new_plane_state->uapi.src_h ||
>> + old_plane_state->uapi.src_x != new_plane_state->uapi.src_x ||
>> + old_plane_state->uapi.src_y != new_plane_state->uapi.src_y ||
>> + old_plane_state->uapi.crtc_w != new_plane_state->uapi.crtc_w ||
>> + old_plane_state->uapi.crtc_h != new_plane_state->uapi.crtc_h ||
>> + old_plane_state->uapi.crtc_x != new_plane_state->uapi.crtc_x ||
>> + old_plane_state->uapi.crtc_y != new_plane_state->uapi.crtc_y) {
>> + DRM_DEBUG_KMS("Plane size/co-ordinates cannot be changed in async flip\n");
>
> These should check the uapi.src/dst rectangles instead.
> In fact I think just two drm_rect_equals() calls will do here,
> and then I think we can also drop the color_plane[0].x/y checks
> above since they should be the same as checking the src.x1/y1.
>
Sure, I'll make these changes.
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.alpha != new_plane_state->hw.alpha) {
>> + DRM_DEBUG_KMS("Alpha value cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.pixel_blend_mode !=
>> + new_plane_state->hw.pixel_blend_mode) {
>> + DRM_DEBUG_KMS("Pixel blend mode cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.color_encoding != new_plane_state->hw.color_encoding) {
>> + DRM_DEBUG_KMS("Color encoding cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (old_plane_state->hw.color_range != new_plane_state->hw.color_range) {
>> + DRM_DEBUG_KMS("Color range cannot be changed in async flip\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /**
>> * intel_atomic_check - validate state object
>> * @dev: drm device
>> @@ -15053,6 +15189,13 @@ static int intel_atomic_check(struct drm_device *dev,
>> "[modeset]" : "[fastset]");
>> }
>>
>> + for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
>> + if (new_crtc_state->uapi.async_flip) {
>> + ret = intel_atomic_check_async(state);
>> + if (ret)
>> + goto fail;
>> + }
>> + }
>
> I would put this before the state dump above. Could even stick it into
> the same loop I guess.
>
Sure, I'll move this into the above loop.
Thanks,
Karthik.B.S
>> return 0;
>>
>> fail:
>> --
>> 2.22.0
>
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