From: Todd Previte Date: Wed, 15 Apr 2015 15:38:41 +0000 (-0700) Subject: drm/i915: Add a delay in Displayport AUX transactions for compliance testing X-Git-Tag: omap-for-v4.2/fixes-rc1^2~17^2~58^2~24 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74ebf294a1dd816bdc248ac733009a8915d59eb5;p=pandora-kernel.git drm/i915: Add a delay in Displayport AUX transactions for compliance testing The Displayport Link Layer Compliance Testing Specification 1.2 rev 1.1 specifies that repeated AUX transactions after a failure (no response / invalid response) must have a minimum delay of 400us before the resend can occur. Tests 4.2.1.1 and 4.2.1.2 are two tests that require this specifically. Also, the check for DP_AUX_CH_CTL_TIME_OUT_ERROR has been moved out into a separate case. This case just continues with the next iteration of the loop as the HW has already waited the required amount of time. V2: - Changed udelay() to usleep_range() V3: - Removed extraneous check for timeout - Updated comment to reflect this change V4: - Reformatted a comment V5: - Added separate check for HW timeout on AUX transactions. A message is logged upon detection of this case. V6: - Add continue statement to HW timeout detect case - Remove the log message indicating a timeout has been detected (review feedback) V7: - Updated the commit message to remove verbage about the HW timeout case that is no longer valid. Signed-off-by: Todd Previte Reviewed-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed