From: Ville Syrjälä Date: Wed, 26 Jun 2013 14:43:24 +0000 (+0300) Subject: drm/i915: Use wait_for() to wait for Punit to change GPU freq on VLV X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e8474409d7ab6dac38d4a3a6a365504b302f6c16;p=linux-beck.git drm/i915: Use wait_for() to wait for Punit to change GPU freq on VLV Use wait_for() instead of the open coded loop to avoid spreading the same old timeout related bugs. This changes the loop to use msleep(1) instead of udelay(10) when the Punit had not yet completed the frequency change. In practice that doesn't seem to hurt performance as the Punit appears to be ready pretty much always. Also give the status bit a name, instead of using the magic number 1. Signed-off-by: Ville Syrjälä Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index f2326fc60ac9..9b51be800961 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -363,6 +363,7 @@ #define PUNIT_REG_GPU_LFM 0xd3 #define PUNIT_REG_GPU_FREQ_REQ 0xd4 #define PUNIT_REG_GPU_FREQ_STS 0xd8 +#define GENFREQSTATUS (1<<0) #define PUNIT_REG_MEDIA_TURBO_FREQ_REQ 0xdc #define PUNIT_FUSE_BUS2 0xf6 /* bits 47:40 */ diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 5b4ade682bd6..7cfd3b74d9b7 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3075,19 +3075,12 @@ void gen6_set_rps(struct drm_device *dev, u8 val) */ static void vlv_update_rps_cur_delay(struct drm_i915_private *dev_priv) { - unsigned long timeout = jiffies + msecs_to_jiffies(10); u32 pval; WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock)); - do { - pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); - if (time_after(jiffies, timeout)) { - DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); - break; - } - udelay(10); - } while (pval & 1); + if (wait_for(((pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS)) & GENFREQSTATUS) == 0, 10)) + DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); pval >>= 8;