diff options
| author | George Shen <george.shen@amd.com> | 2019-11-15 18:56:57 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-12-05 18:23:43 -0500 |
| commit | 0df62823630d03d58f6eedb99fab285f847e4a1b (patch) | |
| tree | c1301bbf43a74de1598c95b32b44c2a0559ebd88 /drivers/gpu/drm/amd | |
| parent | 44ce6c3dc8479bb3ed68df13b502b0901675e7d6 (diff) | |
| download | linux-0df62823630d03d58f6eedb99fab285f847e4a1b.tar.bz2 | |
drm/amd/display: Increase the number of retries after AUX DEFER
[Why]
When a timeout occurs after a DEFER, some devices require more retries
than in the case of a regular timeout.
[How]
In a timeout occurrence, check whether a DEFER has occurred before the
timeout and retry MAX_DEFER_RETRIES retries times instead of
MAX_TIMEOUT_RETRIES.
Signed-off-by: George Shen <george.shen@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Abdoulaye Berthe <Abdoulaye.Berthe@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c index e472608faf33..46a603bfa4bd 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c @@ -583,6 +583,8 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc, uint8_t reply; bool payload_reply = true; enum aux_channel_operation_result operation_result; + bool retry_on_defer = false; + int aux_ack_retries = 0, aux_defer_retries = 0, aux_i2c_defer_retries = 0, @@ -613,8 +615,9 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc, break; case AUX_TRANSACTION_REPLY_AUX_DEFER: - case AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK: case AUX_TRANSACTION_REPLY_I2C_OVER_AUX_DEFER: + retry_on_defer = true; + case AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK: if (++aux_defer_retries >= AUX_MAX_DEFER_RETRIES) { goto fail; } else { @@ -647,15 +650,24 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc, break; case AUX_CHANNEL_OPERATION_FAILED_TIMEOUT: - if (++aux_timeout_retries >= AUX_MAX_TIMEOUT_RETRIES) - goto fail; - else { - /* - * DP 1.4, 2.8.2: AUX Transaction Response/Reply Timeouts - * According to the DP spec there should be 3 retries total - * with a 400us wait inbetween each. Hardware already waits - * for 550us therefore no wait is required here. - */ + // Check whether a DEFER had occurred before the timeout. + // If so, treat timeout as a DEFER. + if (retry_on_defer) { + if (++aux_defer_retries >= AUX_MAX_DEFER_RETRIES) + goto fail; + else if (payload->defer_delay > 0) + msleep(payload->defer_delay); + } else { + if (++aux_timeout_retries >= AUX_MAX_TIMEOUT_RETRIES) + goto fail; + else { + /* + * DP 1.4, 2.8.2: AUX Transaction Response/Reply Timeouts + * According to the DP spec there should be 3 retries total + * with a 400us wait inbetween each. Hardware already waits + * for 550us therefore no wait is required here. + */ + } } break; |