* Re: [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training
2023-08-08 22:19 [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training Kuogee Hsieh
@ 2023-08-25 20:44 ` Abhinav Kumar
2023-08-25 22:15 ` Stephen Boyd
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Abhinav Kumar @ 2023-08-25 20:44 UTC (permalink / raw)
To: Kuogee Hsieh, robdclark, sean, swboyd, dianders, vkoul, daniel,
airlied, agross, dmitry.baryshkov, andersson, marijn.suijten
Cc: quic_jesszhan, quic_sbillaka, freedreno, dri-devel, linux-arm-msm,
linux-kernel
On 8/8/2023 3:19 PM, Kuogee Hsieh wrote:
> DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> cause PLL unlocked initially and then PLL gets locked at the end of
> initialization. PLL_UNLOCKED interrupt will fire during this time if the
> interrupt mask is enabled.
There should be a line break here.
> However currently DP driver link training implementation incorrectly
> re-initializes PHY unconditionally during link training as the PHY was
> already configured in dp_ctrl_enable_mainlink_clocks().
>
> Fix this by re-initializing the PHY only if the previous link training
> failed.
>
> [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
I tested and confirm that without this patch, I see this spam atleast
once per reboot but after this patch, I have not seen this for 5
consecutive reboots.
Hence,
Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280
Looking at the code flow, the dp_ctrl_reinitialize_mainlink() certainly
looks redundant where it is, considering that the clks were enabled just
a couple of lines above in dp_ctrl_enable_mainlink_clocks().
Hence with the minor fix in the commit,
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
> drivers/gpu/drm/msm/dp/dp_ctrl.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index a7a5c7e..77a8d93 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -1774,13 +1774,6 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> return rc;
>
> while (--link_train_max_retries) {
> - rc = dp_ctrl_reinitialize_mainlink(ctrl);
> - if (rc) {
> - DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n",
> - rc);
> - break;
> - }
> -
> training_step = DP_TRAINING_NONE;
> rc = dp_ctrl_setup_main_link(ctrl, &training_step);
> if (rc == 0) {
> @@ -1832,6 +1825,12 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> /* stop link training before start re training */
> dp_ctrl_clear_training_pattern(ctrl);
> }
> +
> + rc = dp_ctrl_reinitialize_mainlink(ctrl);
> + if (rc) {
> + DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n", rc);
> + break;
> + }
> }
>
> if (ctrl->link->sink_request & DP_TEST_LINK_PHY_TEST_PATTERN)
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training
2023-08-08 22:19 [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training Kuogee Hsieh
2023-08-25 20:44 ` Abhinav Kumar
@ 2023-08-25 22:15 ` Stephen Boyd
2023-09-03 21:51 ` Dmitry Baryshkov
2023-10-03 9:10 ` Johan Hovold
3 siblings, 0 replies; 6+ messages in thread
From: Stephen Boyd @ 2023-08-25 22:15 UTC (permalink / raw)
To: Kuogee Hsieh, agross, airlied, andersson, daniel, dianders,
dmitry.baryshkov, marijn.suijten, robdclark, sean, vkoul
Cc: quic_abhinavk, quic_jesszhan, quic_sbillaka, freedreno, dri-devel,
linux-arm-msm, linux-kernel
Quoting Kuogee Hsieh (2023-08-08 15:19:50)
> DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> cause PLL unlocked initially and then PLL gets locked at the end of
> initialization. PLL_UNLOCKED interrupt will fire during this time if the
> interrupt mask is enabled.
> However currently DP driver link training implementation incorrectly
> re-initializes PHY unconditionally during link training as the PHY was
> already configured in dp_ctrl_enable_mainlink_clocks().
>
> Fix this by re-initializing the PHY only if the previous link training
> failed.
>
> [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training
2023-08-08 22:19 [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training Kuogee Hsieh
2023-08-25 20:44 ` Abhinav Kumar
2023-08-25 22:15 ` Stephen Boyd
@ 2023-09-03 21:51 ` Dmitry Baryshkov
2023-10-03 9:10 ` Johan Hovold
3 siblings, 0 replies; 6+ messages in thread
From: Dmitry Baryshkov @ 2023-09-03 21:51 UTC (permalink / raw)
To: Kuogee Hsieh, robdclark, sean, swboyd, dianders, vkoul, daniel,
airlied, agross, andersson, marijn.suijten
Cc: quic_abhinavk, quic_jesszhan, quic_sbillaka, freedreno, dri-devel,
linux-arm-msm, linux-kernel
On 09/08/2023 01:19, Kuogee Hsieh wrote:
> DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> cause PLL unlocked initially and then PLL gets locked at the end of
> initialization. PLL_UNLOCKED interrupt will fire during this time if the
> interrupt mask is enabled.
> However currently DP driver link training implementation incorrectly
> re-initializes PHY unconditionally during link training as the PHY was
> already configured in dp_ctrl_enable_mainlink_clocks().
>
> Fix this by re-initializing the PHY only if the previous link training
> failed.
>
> [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
> drivers/gpu/drm/msm/dp/dp_ctrl.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
--
With best wishes
Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training
2023-08-08 22:19 [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training Kuogee Hsieh
` (2 preceding siblings ...)
2023-09-03 21:51 ` Dmitry Baryshkov
@ 2023-10-03 9:10 ` Johan Hovold
2023-10-13 12:06 ` Johan Hovold
3 siblings, 1 reply; 6+ messages in thread
From: Johan Hovold @ 2023-10-03 9:10 UTC (permalink / raw)
To: Kuogee Hsieh
Cc: robdclark, sean, swboyd, dianders, vkoul, daniel, airlied, agross,
dmitry.baryshkov, andersson, marijn.suijten, quic_abhinavk,
quic_jesszhan, quic_sbillaka, freedreno, dri-devel, linux-arm-msm,
linux-kernel
On Tue, Aug 08, 2023 at 03:19:50PM -0700, Kuogee Hsieh wrote:
> DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> cause PLL unlocked initially and then PLL gets locked at the end of
> initialization. PLL_UNLOCKED interrupt will fire during this time if the
> interrupt mask is enabled.
> However currently DP driver link training implementation incorrectly
> re-initializes PHY unconditionally during link training as the PHY was
> already configured in dp_ctrl_enable_mainlink_clocks().
>
> Fix this by re-initializing the PHY only if the previous link training
> failed.
>
> [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
This fixes the above warning and avoids the unnecessary PHY power-off
and power-on during boot of the ThinkPad X13s:
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
I guess this one should go to stable as well:
Cc: stable@vger.kernel.org # 5.10
Is anyone planning on getting this fixed in 6.6-rc? I noticed that this
one still hasn't shown up linux-next.
> ---
> drivers/gpu/drm/msm/dp/dp_ctrl.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index a7a5c7e..77a8d93 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -1774,13 +1774,6 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> return rc;
>
> while (--link_train_max_retries) {
> - rc = dp_ctrl_reinitialize_mainlink(ctrl);
> - if (rc) {
> - DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n",
> - rc);
> - break;
> - }
> -
> training_step = DP_TRAINING_NONE;
> rc = dp_ctrl_setup_main_link(ctrl, &training_step);
> if (rc == 0) {
> @@ -1832,6 +1825,12 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> /* stop link training before start re training */
> dp_ctrl_clear_training_pattern(ctrl);
> }
> +
> + rc = dp_ctrl_reinitialize_mainlink(ctrl);
> + if (rc) {
> + DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n", rc);
> + break;
> + }
> }
>
> if (ctrl->link->sink_request & DP_TEST_LINK_PHY_TEST_PATTERN)
Johan
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training
2023-10-03 9:10 ` Johan Hovold
@ 2023-10-13 12:06 ` Johan Hovold
0 siblings, 0 replies; 6+ messages in thread
From: Johan Hovold @ 2023-10-13 12:06 UTC (permalink / raw)
To: Kuogee Hsieh
Cc: robdclark, sean, swboyd, dianders, vkoul, daniel, airlied, agross,
dmitry.baryshkov, andersson, marijn.suijten, quic_abhinavk,
quic_jesszhan, quic_sbillaka, freedreno, dri-devel, linux-arm-msm,
linux-kernel
On Tue, Oct 03, 2023 at 11:10:59AM +0200, Johan Hovold wrote:
> On Tue, Aug 08, 2023 at 03:19:50PM -0700, Kuogee Hsieh wrote:
> > DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> > cause PLL unlocked initially and then PLL gets locked at the end of
> > initialization. PLL_UNLOCKED interrupt will fire during this time if the
> > interrupt mask is enabled.
> > However currently DP driver link training implementation incorrectly
> > re-initializes PHY unconditionally during link training as the PHY was
> > already configured in dp_ctrl_enable_mainlink_clocks().
> >
> > Fix this by re-initializing the PHY only if the previous link training
> > failed.
> >
> > [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
> >
> > Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> > Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
>
> This fixes the above warning and avoids the unnecessary PHY power-off
> and power-on during boot of the ThinkPad X13s:
>
> Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
> Tested-by: Johan Hovold <johan+linaro@kernel.org>
>
> I guess this one should go to stable as well:
>
> Cc: stable@vger.kernel.org # 5.10
>
> Is anyone planning on getting this fixed in 6.6-rc? I noticed that this
> one still hasn't shown up linux-next.
For the record, this one showed up in a PR from Rob and has now been
forwarded to Linus.
No stable tag included, but I guess we can ping the stable team unless
AUTOSEL picks this up.
Johan
^ permalink raw reply [flat|nested] 6+ messages in thread