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Groups > linux.kernel > #1712527
| From | Eric Anholt <eric@anholt.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math. |
| Date | 2017-08-16 02:00 +0200 |
| Message-ID | <ueTUB-7Wz-9@gated-at.bofh.it> (permalink) |
| References | <ueTUB-7Wz-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
The incoming mode might have a missing vrefresh field if it came from drmModeSetCrtc(), which the kernel is supposed to calculate using drm_mode_vrefresh(). We could either use that or the adjusted_mode's original vrefresh value. However, we can maintain a more exact vrefresh value (not just the integer approximation), by scaling by the ratio of our clocks. v2: Use math suggested by Andrzej Hajda instead. v3: Simplify math now that adjusted_mode->clock isn't padded. Signed-off-by: Eric Anholt <eric@anholt.net> --- drivers/gpu/drm/vc4/vc4_dsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index eb787eed8abe..2516cd3a1d87 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -862,7 +862,8 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder, adjusted_mode->clock = pixel_clock_hz / 1000; /* Given the new pixel clock, adjust HFP to keep vrefresh the same. */ - adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal); + adjusted_mode->htotal = (adjusted_mode->clock * mode->htotal / + mode->clock); adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal; adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal; -- 2.14.1
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[PATCH v6 1/5] drm/vc4: Move the DSI clock divider workaround closer to the clock call. Eric Anholt <eric@anholt.net> - 2017-08-16 02:00 +0200
[PATCH v6 5/5] drm/panel: Add support for the Raspberry Pi 7" Touchscreen. Eric Anholt <eric@anholt.net> - 2017-08-16 02:00 +0200
[PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math. Eric Anholt <eric@anholt.net> - 2017-08-16 02:00 +0200
Re: [PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math. Andrzej Hajda <a.hajda@samsung.com> - 2017-08-16 09:00 +0200
[PATCH v6 4/5] dt-bindings: Document the Raspberry Pi Touchscreen nodes. Eric Anholt <eric@anholt.net> - 2017-08-16 02:00 +0200
[PATCH v6 3/5] drm/vc4: Set up the DSI host at pdev probe time, not component bind. Eric Anholt <eric@anholt.net> - 2017-08-16 02:00 +0200
Re: [PATCH v6 3/5] drm/vc4: Set up the DSI host at pdev probe time, not component bind. Archit Taneja <architt@codeaurora.org> - 2017-08-17 05:50 +0200
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