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[PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

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  [PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround closer to the clock call. Eric Anholt <eric@anholt.net> - 2017-09-27 21:40 +0200
    Re: [PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround  closer to the clock call. Thierry Reding <thierry.reding@gmail.com> - 2017-09-28 15:00 +0200
      Re: [PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround closer to the clock call. Eric Anholt <eric@anholt.net> - 2017-09-28 19:30 +0200

#1740966 — [PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

We want the adjusted_mode->clock to be the actual clock we're
expecting to program, so that consumers see the right values for clock
and vrefresh.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 925c726ac694..554605af344e 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -859,11 +859,7 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
 	pll_clock = parent_rate / divider;
 	pixel_clock_hz = pll_clock / dsi->divider;
 
-	/* Round up the clk_set_rate() request slightly, since
-	 * PLLD_DSI1 is an integer divider and its rate selection will
-	 * never round up.
-	 */
-	adjusted_mode->clock = pixel_clock_hz / 1000 + 1;
+	adjusted_mode->clock = pixel_clock_hz / 1000;
 
 	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
 	adjusted_mode->htotal = adjusted_mode->clock * mode->htotal /
@@ -901,7 +897,11 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
 		vc4_dsi_dump_regs(dsi);
 	}
 
-	phy_clock = pixel_clock_hz * dsi->divider;
+	/* Round up the clk_set_rate() request slightly, since
+	 * PLLD_DSI1 is an integer divider and its rate selection will
+	 * never round up.
+	 */
+	phy_clock = (pixel_clock_hz + 1000) * dsi->divider;
 	ret = clk_set_rate(dsi->pll_phy_clock, phy_clock);
 	if (ret) {
 		dev_err(&dsi->pdev->dev,
-- 
2.14.1

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#1741515 — Re: [PATCH v6 1/3] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

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On Wed, Sep 27, 2017 at 12:36:52PM -0700, Eric Anholt wrote:
> We want the adjusted_mode->clock to be the actual clock we're
> expecting to program, so that consumers see the right values for clock
> and vrefresh.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

Do you want me to apply this to drm-misc-next along with the touchscreen
panel driver?

Thierry

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#1741725

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Thierry Reding <thierry.reding@gmail.com> writes:

> [ Unknown signature status ]
> On Wed, Sep 27, 2017 at 12:36:52PM -0700, Eric Anholt wrote:
>> We want the adjusted_mode->clock to be the actual clock we're
>> expecting to program, so that consumers see the right values for clock
>> and vrefresh.
>> 
>> Signed-off-by: Eric Anholt <eric@anholt.net>
>> ---
>>  drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
>>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> Do you want me to apply this to drm-misc-next along with the touchscreen
> panel driver?

drm-misc-next procedure trends toward the submitter applies the patch
once they get review, if they have the commit rights.  However, I'm
happy either way as long as I can get the code in.

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