diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-07-22 10:35:41 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-10-09 17:17:32 +0100 |
| commit | d0c96d168021a60555c692d860334814cc694d8b (patch) | |
| tree | 4a96ebe82ea94f3c8f78e99f99cf922ac8942d08 /drivers/gpu/drm/bridge | |
| parent | 91cd69088ecc375d057eb3721bfbcf927e9f2dd2 (diff) | |
drm: bridge/dw_hdmi: avoid being recursive in N calculation
There's no need to be recursive when computing the N value for the ACR
packet - we can instead calculate the multiplier prior to our switch()
based lookup, and multiply the N value appropriately afterwards.
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/gpu/drm/bridge')
| -rw-r--r-- | drivers/gpu/drm/bridge/dw_hdmi.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 70e7a938a37b..e5ee92370f49 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -221,6 +221,12 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, unsigned int ratio) { unsigned int n = (128 * freq) / 1000; + unsigned int mult = 1; + + while (freq > 48000) { + mult *= 2; + freq /= 2; + } switch (freq) { case 32000: @@ -232,6 +238,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, n = 11648; else n = 4096; + n *= mult; break; case 44100: @@ -243,6 +250,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, n = (ratio == 150) ? 17836 : 8918; else n = 6272; + n *= mult; break; case 48000: @@ -256,22 +264,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, n = (ratio == 150) ? 11648 : 5824; else n = 6144; - break; - - case 88200: - n = hdmi_compute_n(44100, pixel_clk, ratio) * 2; - break; - - case 96000: - n = hdmi_compute_n(48000, pixel_clk, ratio) * 2; - break; - - case 176400: - n = hdmi_compute_n(44100, pixel_clk, ratio) * 4; - break; - - case 192000: - n = hdmi_compute_n(48000, pixel_clk, ratio) * 4; + n *= mult; break; default: |