From 8cbeb06dc6b584009d7492c667a3c9a4b96cdefa Mon Sep 17 00:00:00 2001 From: "Pandiyan, Dhinakaran" Date: Tue, 14 Mar 2017 15:45:56 -0700 Subject: [PATCH] drm/i915: Implement cdclk restrictions based on Azalia BCLK According to BSpec, "The CD clock frequency must be at least twice the frequency of the Azalia BCLK." and BCLK is configured to 96 MHz by default. This check is needed because BXT and GLK support cdclk frequencies less than 192 MHz. v2: Include other Gen9 platforms too for completeness.(Paulo) Cc: Paulo Zanoni Signed-off-by: Dhinakaran Pandiyan Reviewed-by: Paulo Zanoni Signed-off-by: Paulo Zanoni Link: http://patchwork.freedesktop.org/patch/msgid/1489531556-2926-1-git-send-email-dhinakaran.pandiyan@intel.com --- drivers/gpu/drm/i915/intel_cdclk.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index dd350642eba1..dd3ad52b7dfe 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -1458,6 +1458,18 @@ static int bdw_adjust_min_pipe_pixel_rate(struct intel_crtc_state *crtc_state, pixel_rate = max(432000, pixel_rate); } + /* According to BSpec, "The CD clock frequency must be at least twice + * the frequency of the Azalia BCLK." and BCLK is 96 MHz by default. + * The check for GLK has to be adjusted as the platform can output + * two pixels per clock. + */ + if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9) { + if (IS_GEMINILAKE(dev_priv)) + pixel_rate = max(2 * 2 * 96000, pixel_rate); + else + pixel_rate = max(2 * 96000, pixel_rate); + } + return pixel_rate; } -- GitLab