diff options
| author | Jani Nikula <jani.nikula@intel.com> | 2014-02-11 11:52:05 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-03-05 17:13:57 +0100 |
| commit | 04ea7f8d985ba915d9eebec9ae724e996d1a5404 (patch) | |
| tree | 115d6ba07af77f819899dd642817835f8d98d565 | |
| parent | 4a036dd40a68428a35f3272a3275b3f35099dd43 (diff) | |
drm/i915/dp: add native aux defer retry limit
commit f51a44b9a6c4982cc25bfb3727de9bb893621ebc upstream.
Retrying indefinitely places too much trust on the aux implementation of
the sink devices.
Reported-by: Daniel Martin <consume.noise@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71267
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Sree Harsha Totakura <freedesktop@h.totakura.in>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index e5c79ae1614..b0191f25cd5 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -450,6 +450,7 @@ intel_dp_aux_native_write(struct intel_dp *intel_dp, uint8_t msg[20]; int msg_bytes; uint8_t ack; + int retry; intel_dp_check_edp(intel_dp); if (send_bytes > 16) @@ -460,18 +461,20 @@ intel_dp_aux_native_write(struct intel_dp *intel_dp, 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 */ @@ -493,6 +496,7 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp, int reply_bytes; uint8_t ack; int ret; + int retry; intel_dp_check_edp(intel_dp); msg[0] = AUX_NATIVE_READ << 4; @@ -503,7 +507,7 @@ intel_dp_aux_native_read(struct intel_dp *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) @@ -520,6 +524,9 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp, else return -EIO; } + + DRM_ERROR("too many retries, giving up\n"); + return -EIO; } static int |