[PATCH 6/9] drm: bridge/dw_hdmi: adjust pixel clock values in N calculation

From: Russell King
Date: Sat Aug 08 2015 - 12:11:21 EST


Adjust the pixel clock values in the N calculation to match the more
accurate clock values we're given by the DRM subsystem, which are the
kHz pixel rate, with any fractional kHz rounded down in the case of
the non-240, non-480 line modes, or rounded up for the others. So,

25.20 / 1.001 => 25175
27.00 * 1.001 => 27027
74.25 / 1.001 => 74176
148.50 / 1.001 => 148352

Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/dw_hdmi.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c
index f0e6059f818a..5576cd7d7abb 100644
--- a/drivers/gpu/drm/bridge/dw_hdmi.c
+++ b/drivers/gpu/drm/bridge/dw_hdmi.c
@@ -230,11 +230,11 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk,

switch (freq) {
case 32000:
- if (pixel_clk == 25170000)
+ if (pixel_clk == 25175000)
n = (ratio == 150) ? 9152 : 4576;
- else if (pixel_clk == 27020000)
+ else if (pixel_clk == 27027000)
n = (ratio == 150) ? 8192 : 4096;
- else if (pixel_clk == 74170000 || pixel_clk == 148350000)
+ else if (pixel_clk == 74176000 || pixel_clk == 148352000)
n = 11648;
else
n = 4096;
@@ -242,11 +242,11 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk,
break;

case 44100:
- if (pixel_clk == 25170000)
+ if (pixel_clk == 25175000)
n = 7007;
- else if (pixel_clk == 74170000)
+ else if (pixel_clk == 74176000)
n = 17836;
- else if (pixel_clk == 148350000)
+ else if (pixel_clk == 148352000)
n = (ratio == 150) ? 17836 : 8918;
else
n = 6272;
@@ -254,13 +254,13 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk,
break;

case 48000:
- if (pixel_clk == 25170000)
+ if (pixel_clk == 25175000)
n = (ratio == 150) ? 9152 : 6864;
- else if (pixel_clk == 27020000)
+ else if (pixel_clk == 27027000)
n = (ratio == 150) ? 8192 : 6144;
- else if (pixel_clk == 74170000)
+ else if (pixel_clk == 74176000)
n = 11648;
- else if (pixel_clk == 148350000)
+ else if (pixel_clk == 148352000)
n = (ratio == 150) ? 11648 : 5824;
else
n = 6144;
--
2.1.0

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