Patch "drm/radeon: retry dcpd fetch" has been added to the 4.0-stable tree

Patch "drm/radeon: retry dcpd fetch" has been added to the 4.0-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/radeon: retry dcpd fetch

to the 4.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-radeon-retry-dcpd-fetch.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0f28d1281b6c54cc98746ae61e44e7f540758ed4 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Mon, 18 May 2015 10:38:25 -0400
Subject: drm/radeon: retry dcpd fetch

From: Alex Deucher <alexander.deucher@amd.com>

commit 0f28d1281b6c54cc98746ae61e44e7f540758ed4 upstream.

Retry the dpcd fetch several times.  Some eDP panels
fail several times before the fetch is successful.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=73530

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/radeon/atombios_dp.c |   20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -412,19 +412,21 @@ bool radeon_dp_getdpcd(struct radeon_con
 {
 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
 	u8 msg[DP_DPCD_SIZE];
-	int ret;
+	int ret, i;
 
-	ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
-			       DP_DPCD_SIZE);
-	if (ret > 0) {
-		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
+	for (i = 0; i < 7; i++) {
+		ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
+				       DP_DPCD_SIZE);
+		if (ret == DP_DPCD_SIZE) {
+			memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
 
-		DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
-			      dig_connector->dpcd);
+			DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
+				      dig_connector->dpcd);
 
-		radeon_dp_probe_oui(radeon_connector);
+			radeon_dp_probe_oui(radeon_connector);
 
-		return true;
+			return true;
+		}
 	}
 	dig_connector->dpcd[0] = 0;
 	return false;


Patches currently in stable-queue which might be from alexander.deucher@amd.com are

queue-4.0/drm-radeon-partially-revert-fix-vm_context-_page_table_end_addr-handling.patch
queue-4.0/drm-radeon-don-t-share-plls-if-monitors-differ-in-audio-support.patch
queue-4.0/drm-radeon-audio-make-sure-connector-is-valid-in-hotplug-case.patch
queue-4.0/drm-radeon-fix-vm_context-_page_table_end_addr-handling.patch
queue-4.0/drm-radeon-add-new-bonaire-pci-id.patch
queue-4.0/revert-drm-radeon-only-mark-audio-as-connected-if-the-monitor-supports-it-v3.patch
queue-4.0/drm-amdkfd-don-t-report-local-memory-size.patch
queue-4.0/drm-radeon-retry-dcpd-fetch.patch