From: Chris Wilson Date: Thu, 16 Feb 2017 12:54:41 +0000 (+0000) Subject: drm/i915: Squelch any ktime/jiffie rounding errors for wait-ioctl X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c1d2061b28c2aa25ec39b60d9c248e6beebd7315;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git drm/i915: Squelch any ktime/jiffie rounding errors for wait-ioctl We wait upon jiffies, but report the time elapsed using a high-resolution timer. This discrepancy can lead to us timing out the wait prior to us reporting the elapsed time as complete. This restores the squelching lost in commit e95433c73a11 ("drm/i915: Rearrange i915_wait_request() accounting with callers"). Fixes: e95433c73a11 ("drm/i915: Rearrange i915_wait_request() accounting with callers") Signed-off-by: Chris Wilson Cc: Matthew Auld Cc: Joonas Lahtinen Cc: # v4.10-rc1+ Cc: stable@vger.kernel.org Link: http://patchwork.freedesktop.org/patch/msgid/20170216125441.30923-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 71297920fdf4..e6b8a4f56bbe 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3072,6 +3072,16 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) args->timeout_ns -= ktime_to_ns(ktime_sub(ktime_get(), start)); if (args->timeout_ns < 0) args->timeout_ns = 0; + + /* + * Apparently ktime isn't accurate enough and occasionally has a + * bit of mismatch in the jiffies<->nsecs<->ktime loop. So patch + * things up to make the test happy. We allow up to 1 jiffy. + * + * This is a regression from the timespec->ktime conversion. + */ + if (ret == -ETIME && !nsecs_to_jiffies(args->timeout_ns)) + args->timeout_ns = 0; } i915_gem_object_put(obj);