Messages in this thread | | | Date | Thu, 08 Jul 2021 14:59:53 -0700 | From | khsieh@codeauro ... | Subject | Re: [PATCH 3/7] drm/msm/dp: reset aux controller after dp_aux_cmd_fifo_tx() failed. |
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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@codeaurora.org> >> --- >> 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) { >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project >>
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