From d7baedcdebe4d02fb08342aa8d1fbf9e535872be Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 15 Apr 2016 11:41:06 +0300 Subject: [PATCH] drm/i915: Update CDCLK_FREQ register on BDW after changing cdclk frequency MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Update CDCLK_FREQ on BDW after changing the cdclk frequency. Not sure if this is a late addition to the spec, or if I simply overlooked this step when writing the original code. This is what Bspec has to say about CDCLK_FREQ: "Program this field to the CD clock frequency minus one. This is used to generate a divided down clock for miscellaneous timers in display." And the "Broadwell Sequences for Changing CD Clock Frequency" section clarifies this further: "For CD clock 337.5 MHz, program 337 decimal. For CD clock 450 MHz, program 449 decimal. For CD clock 540 MHz, program 539 decimal. For CD clock 675 MHz, program 674 decimal." Cc: stable@vger.kernel.org Cc: Lu, Han Cc: Vasily Khoruzhick Cc: Mika Kahola Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91410 Fixes: b432e5cfd5e9 ("drm/i915: BDW clock change support") Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/i915/i915_reg.h | 2 ++ drivers/gpu/drm/i915/intel_display.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 03264fd30fdd..41c9ae03652b 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7484,6 +7484,8 @@ enum skl_disp_power_wells { #define TRANS_CLK_SEL_DISABLED (0x0<<29) #define TRANS_CLK_SEL_PORT(x) (((x)+1)<<29) +#define CDCLK_FREQ _MMIO(0x46200) + #define _TRANSA_MSA_MISC 0x60410 #define _TRANSB_MSA_MISC 0x61410 #define _TRANSC_MSA_MISC 0x62410 diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 929fd93b3e5d..ea55dd331fac 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9647,6 +9647,8 @@ static void broadwell_set_cdclk(struct drm_device *dev, int cdclk) sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, data); mutex_unlock(&dev_priv->rps.hw_lock); + I915_WRITE(CDCLK_FREQ, DIV_ROUND_CLOSEST(cdclk, 1000) - 1); + intel_update_cdclk(dev); WARN(cdclk != dev_priv->cdclk_freq, -- 2.7.4