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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2010-08-07 11:01:35 +0100 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2010-08-09 11:24:35 -0700 |
| commit | 913d8d110078788c14812dce8bb62c37946821d2 (patch) | |
| tree | 982a622078194b438bf75d0ee4c77cf1e4f0260e /drivers/gpu/drm/i915/intel_dp.c | |
| parent | dd785e35cb3c430c2290d351e67715864f7e5db5 (diff) | |
| download | lwn-913d8d110078788c14812dce8bb62c37946821d2.tar.gz lwn-913d8d110078788c14812dce8bb62c37946821d2.zip | |
drm/i915: Ensure that while(INREG()) are bounded (v2)
Add a new macro, wait_for, to simplify the act of waiting on a register
to change state. wait_for() takes three arguments, the condition to
inspect on every loop, the maximum amount of time to wait and whether to
yield the cpu for a length of time after each check.
v2: Upgrade failure messages to DRM_ERROR on the suggestion of
Eric Anholt. We do not expect to hit these conditions as they reflect
programming errors, so if we do we want to be notified.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index cee5d9ceb3b8..c6629bd9430f 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -759,22 +759,18 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode, static void ironlake_edp_panel_on (struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; - unsigned long timeout = jiffies + msecs_to_jiffies(5000); - u32 pp, pp_status; + u32 pp; - pp_status = I915_READ(PCH_PP_STATUS); - if (pp_status & PP_ON) + if (I915_READ(PCH_PP_STATUS) & PP_ON) return; pp = I915_READ(PCH_PP_CONTROL); pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON; I915_WRITE(PCH_PP_CONTROL, pp); - do { - pp_status = I915_READ(PCH_PP_STATUS); - } while (((pp_status & PP_ON) == 0) && !time_after(jiffies, timeout)); - if (time_after(jiffies, timeout)) - DRM_DEBUG_KMS("panel on wait timed out: 0x%08x\n", pp_status); + if (wait_for(I915_READ(PCH_PP_STATUS) & PP_ON, 5000, 10)) + DRM_ERROR("panel on wait timed out: 0x%08x\n", + I915_READ(PCH_PP_STATUS)); pp &= ~(PANEL_UNLOCK_REGS | EDP_FORCE_VDD); I915_WRITE(PCH_PP_CONTROL, pp); @@ -783,18 +779,15 @@ static void ironlake_edp_panel_on (struct drm_device *dev) static void ironlake_edp_panel_off (struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; - unsigned long timeout = jiffies + msecs_to_jiffies(5000); - u32 pp, pp_status; + u32 pp; pp = I915_READ(PCH_PP_CONTROL); pp &= ~POWER_TARGET_ON; I915_WRITE(PCH_PP_CONTROL, pp); - do { - pp_status = I915_READ(PCH_PP_STATUS); - } while ((pp_status & PP_ON) && !time_after(jiffies, timeout)); - if (time_after(jiffies, timeout)) - DRM_DEBUG_KMS("panel off wait timed out\n"); + if (wait_for((I915_READ(PCH_PP_STATUS) & PP_ON) == 0, 5000, 10)) + DRM_ERROR("panel off wait timed out: 0x%08x\n", + I915_READ(PCH_PP_STATUS)); /* Make sure VDD is enabled so DP AUX will work */ pp |= EDP_FORCE_VDD; |