drm/radeon/kms: retry auxch on 0x20 timeout value.
authorDave Airlie <airlied@redhat.com>
Wed, 10 Feb 2010 06:52:45 +0000 (16:52 +1000)
committerDave Airlie <airlied@redhat.com>
Thu, 11 Feb 2010 04:03:18 +0000 (14:03 +1000)
ATOM appears to return 0x20 which seems to mean some sort of timeout.

retry the transaction up to 10 times before failing, this
makes DP->VGA convertor we bought work at least a bit more predictably.

Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/radeon/atombios_dp.c

index 7106011..b32eeea 100644 (file)
@@ -332,11 +332,13 @@ bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
        PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION args;
        int index = GetIndexIntoMasterTable(COMMAND, ProcessAuxChannelTransaction);
        unsigned char *base;
+       int retry_count = 0;
 
        memset(&args, 0, sizeof(args));
 
        base = (unsigned char *)rdev->mode_info.atom_context->scratch;
 
+retry:
        memcpy(base, req_bytes, num_bytes);
 
        args.lpAuxRequest = 0;
@@ -347,10 +349,12 @@ bool radeon_process_aux_ch(struct radeon_i2c_chan *chan, u8 *req_bytes,
 
        atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
 
-       if (args.ucReplyStatus) {
-               DRM_DEBUG("failed to get auxch %02x%02x %02x %02x 0x%02x %02x\n",
+       if (args.ucReplyStatus && !args.ucDataOutLen) {
+               if (args.ucReplyStatus == 0x20 && retry_count < 10)
+                       goto retry;
+               DRM_DEBUG("failed to get auxch %02x%02x %02x %02x 0x%02x %02x after %d retries\n",
                          req_bytes[1], req_bytes[0], req_bytes[2], req_bytes[3],
-                         chan->rec.i2c_id, args.ucReplyStatus);
+                         chan->rec.i2c_id, args.ucReplyStatus, retry_count);
                return false;
        }