This is a note to let you know that I've just added the patch titled
drm/i915/dp: add native aux defer retry limit
to the 3.13-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-i915-dp-add-native-aux-defer-retry-limit.patch
and it can be found in the queue-3.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f51a44b9a6c4982cc25bfb3727de9bb893621ebc Mon Sep 17 00:00:00 2001
From: Jani Nikula <[email protected]>
Date: Tue, 11 Feb 2014 11:52:05 +0200
Subject: drm/i915/dp: add native aux defer retry limit
From: Jani Nikula <[email protected]>
commit f51a44b9a6c4982cc25bfb3727de9bb893621ebc upstream.
Retrying indefinitely places too much trust on the aux implementation of
the sink devices.
Reported-by: Daniel Martin <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71267
Signed-off-by: Jani Nikula <[email protected]>
Tested-by: Theodore Ts'o <[email protected]>
Tested-by: Sree Harsha Totakura <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/i915/intel_dp.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -537,6 +537,7 @@ intel_dp_aux_native_write(struct intel_d
uint8_t msg[20];
int msg_bytes;
uint8_t ack;
+ int retry;
if (WARN_ON(send_bytes > 16))
return -E2BIG;
@@ -548,18 +549,20 @@ intel_dp_aux_native_write(struct intel_d
msg[3] = send_bytes - 1;
memcpy(&msg[4], send, send_bytes);
msg_bytes = send_bytes + 4;
- for (;;) {
+ for (retry = 0; retry < 7; retry++) {
ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, &ack, 1);
if (ret < 0)
return ret;
if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
- break;
+ return send_bytes;
else if ((ack & AUX_NATIVE_REPLY_MASK) ==
AUX_NATIVE_REPLY_DEFER)
usleep_range(400, 500);
else
return -EIO;
}
- return send_bytes;
+
+ DRM_ERROR("too many retries, giving up\n");
+ return -EIO;
}
/* Write a single byte to the aux channel in native mode */
@@ -581,6 +584,7 @@ intel_dp_aux_native_read(struct intel_dp
int reply_bytes;
uint8_t ack;
int ret;
+ int retry;
if (WARN_ON(recv_bytes > 19))
return -E2BIG;
@@ -594,7 +598,7 @@ intel_dp_aux_native_read(struct intel_dp
msg_bytes = 4;
reply_bytes = recv_bytes + 1;
- for (;;) {
+ for (retry = 0; retry < 7; retry++) {
ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes,
reply, reply_bytes);
if (ret == 0)
@@ -611,6 +615,9 @@ intel_dp_aux_native_read(struct intel_dp
else
return -EIO;
}
+
+ DRM_ERROR("too many retries, giving up\n");
+ return -EIO;
}
static int
Patches currently in stable-queue which might be from [email protected] are
queue-3.13/drm-i915-dp-increase-native-aux-defer-retry-timeout.patch
queue-3.13/drm-i915-dp-add-native-aux-defer-retry-limit.patch
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