drm/radeon: add a i2c bus mutex
The i2c and aux buses use the same pads so add
a mutex to protect access to the pads.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index bc0119f..330f8df 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -95,9 +95,12 @@
int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
unsigned char *base;
int recv_bytes;
+ int r = 0;
memset(&args, 0, sizeof(args));
+ mutex_lock(&chan->mutex);
+
base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
radeon_atom_copy_swap(base, send, send_bytes, true);
@@ -117,19 +120,22 @@
/* timeout */
if (args.v1.ucReplyStatus == 1) {
DRM_DEBUG_KMS("dp_aux_ch timeout\n");
- return -ETIMEDOUT;
+ r = -ETIMEDOUT;
+ goto done;
}
/* flags not zero */
if (args.v1.ucReplyStatus == 2) {
DRM_DEBUG_KMS("dp_aux_ch flags not zero\n");
- return -EBUSY;
+ r = -EBUSY;
+ goto done;
}
/* error */
if (args.v1.ucReplyStatus == 3) {
DRM_DEBUG_KMS("dp_aux_ch error\n");
- return -EIO;
+ r = -EIO;
+ goto done;
}
recv_bytes = args.v1.ucDataOutLen;
@@ -139,7 +145,11 @@
if (recv && recv_size)
radeon_atom_copy_swap(recv, base + 16, recv_bytes, false);
- return recv_bytes;
+ r = recv_bytes;
+done:
+ mutex_unlock(&chan->mutex);
+
+ return r;
}
#define BARE_ADDRESS_SIZE 3