From 47e9766df0298739aab87c9874a21feb71560953 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 10 Dec 2013 17:02:43 +0200 Subject: [PATCH] drm/i915: Fix timeout with missed interrupts in __wait_seqno MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 094f9a54e355 ("drm/i915: Fix __wait_seqno to use true infinite timeouts") added support for __wait_seqno to detect missing interrupts and go around them by polling. As there is also timeout detection in __wait_seqno, the polling and timeout detection were done with the same timer. When there has been missed interrupts and polling is needed, the timer is set to trigger in (now + 1) jiffies in future, instead of the caller specified timeout. Now when io_schedule() returns, we calculate the jiffies left to timeout using the timer expiration value. As the current jiffies is now bound to be always equal or greater than the expiration value, the timeout_jiffies will become zero or negative and we return -ETIME to caller even tho the timeout was never reached. Fix this by decoupling timeout calculation from timer expiration. v2: Commit message with some sense in it (Chris Wilson) v3: add parenthesis on timeout_expire calculation v4: don't read jiffies without timeout (Chris Wilson) Signed-off-by: Mika Kuoppala Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- Reading git-format-patch failed