On 2021-07-08 00:34, Stephen Boyd wrote:
Quoting Kuogee Hsieh (2021-07-06 10:20:16)
Aux hardware calibration sequence requires resetting the aux
controller
in order for the new setting to take effect. However resetting the AUX
controller will also clear HPD interrupt status which may accidentally
cause pending unplug interrupt to get lost. Therefore reset aux
controller only when link is in connection state when
dp_aux_cmd_fifo_tx()
fail. This fixes Link Layer CTS cases 4.2.1.1 and 4.2.1.2.
Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_aux.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c
b/drivers/gpu/drm/msm/dp/dp_aux.c
index 4a3293b..eb40d84 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -353,6 +353,9 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux
*dp_aux,
if (!(aux->retry_cnt % MAX_AUX_RETRIES))
dp_catalog_aux_update_cfg(aux->catalog);
}
+ /* reset aux if link is in connected state */
+ if (dp_catalog_link_is_connected(aux->catalog))
How do we avoid resetting aux when hpd is unplugged and then plugged
back in during an aux transfer?
i am not sure this is possible.
it should get unplug interrupt followed by plugin interrupt.
In this case, aux will be re set and initialized
+ dp_catalog_aux_reset(aux->catalog);
} else {
aux->retry_cnt = 0;
switch (aux->aux_error_num) {
--
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