The ps8640 bridge seems to expect everything to be power cycled at the
disable process, but sometimes ps8640_aux_transfer() holds the runtime
PM reference and prevents the bridge from suspend.
Prevent that by introducing a mutex lock between ps8640_aux_transfer()
and .post_disable() to make sure the bridge is really powered off.
Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
Signed-off-by: Pin-yen Lin <[email protected]>
---
Changes in v2:
- Use mutex instead of the completion and autosuspend hack
drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 8161b1a1a4b1..46c84ce66041 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -107,6 +107,7 @@ struct ps8640 {
struct device_link *link;
bool pre_enabled;
bool need_post_hpd_delay;
+ struct mutex aux_lock;
};
static const struct regmap_config ps8640_regmap_config[] = {
@@ -344,10 +345,12 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
int ret;
+ mutex_lock(&ps_bridge->aux_lock);
pm_runtime_get_sync(dev);
ret = ps8640_aux_transfer_msg(aux, msg);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
+ mutex_unlock(&ps_bridge->aux_lock);
return ret;
}
@@ -469,7 +472,18 @@ static void ps8640_atomic_post_disable(struct drm_bridge *bridge,
ps_bridge->pre_enabled = false;
ps8640_bridge_vdo_control(ps_bridge, DISABLE);
+
+ /*
+ * The bridge seems to expect everything to be power cycled at the
+ * disable process, so grab a lock here to make sure
+ * ps8640_aux_transfer() is not holding a runtime PM reference and
+ * preventing the bridge from suspend.
+ */
+ mutex_lock(&ps_bridge->aux_lock);
+
pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
+
+ mutex_unlock(&ps_bridge->aux_lock);
}
static int ps8640_bridge_attach(struct drm_bridge *bridge,
@@ -618,6 +632,8 @@ static int ps8640_probe(struct i2c_client *client)
if (!ps_bridge)
return -ENOMEM;
+ mutex_init(&ps_bridge->aux_lock);
+
ps_bridge->supplies[0].supply = "vdd12";
ps_bridge->supplies[1].supply = "vdd33";
ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
--
2.43.0.472.g3155946c3a-goog
Hi,
On Tue, Jan 9, 2024 at 4:05 AM Pin-yen Lin <[email protected]> wrote:
>
> The ps8640 bridge seems to expect everything to be power cycled at the
> disable process, but sometimes ps8640_aux_transfer() holds the runtime
> PM reference and prevents the bridge from suspend.
>
> Prevent that by introducing a mutex lock between ps8640_aux_transfer()
> and .post_disable() to make sure the bridge is really powered off.
>
> Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
> Signed-off-by: Pin-yen Lin <[email protected]>
> ---
>
> Changes in v2:
> - Use mutex instead of the completion and autosuspend hack
>
> drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
This looks OK to me now.
Reviewed-by: Douglas Anderson <[email protected]>
I'll let it stew on the mailing list for ~1 week and then land it in
drm-misc-fixes unless there are additional comments.
-Doug
Hi,
On Tue, Jan 9, 2024 at 8:52 AM Doug Anderson <[email protected]> wrote:
>
> Hi,
>
> On Tue, Jan 9, 2024 at 4:05 AM Pin-yen Lin <[email protected]> wrote:
> >
> > The ps8640 bridge seems to expect everything to be power cycled at the
> > disable process, but sometimes ps8640_aux_transfer() holds the runtime
> > PM reference and prevents the bridge from suspend.
> >
> > Prevent that by introducing a mutex lock between ps8640_aux_transfer()
> > and .post_disable() to make sure the bridge is really powered off.
> >
> > Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
> > Signed-off-by: Pin-yen Lin <[email protected]>
> > ---
> >
> > Changes in v2:
> > - Use mutex instead of the completion and autosuspend hack
> >
> > drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
>
> This looks OK to me now.
>
> Reviewed-by: Douglas Anderson <[email protected]>
>
> I'll let it stew on the mailing list for ~1 week and then land it in
> drm-misc-fixes unless there are additional comments.
Pushed to drm-misc-fixes:
26db46bc9c67 drm/bridge: parade-ps8640: Ensure bridge is suspended in
post_disable()
Hi,
On Wed, Jan 17, 2024 at 9:34 AM Doug Anderson <[email protected]> wrote:
>
> Hi,
>
> On Tue, Jan 9, 2024 at 8:52 AM Doug Anderson <[email protected]> wrote:
> >
> > Hi,
> >
> > On Tue, Jan 9, 2024 at 4:05 AM Pin-yen Lin <[email protected]> wrote:
> > >
> > > The ps8640 bridge seems to expect everything to be power cycled at the
> > > disable process, but sometimes ps8640_aux_transfer() holds the runtime
> > > PM reference and prevents the bridge from suspend.
> > >
> > > Prevent that by introducing a mutex lock between ps8640_aux_transfer()
> > > and .post_disable() to make sure the bridge is really powered off.
> > >
> > > Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
> > > Signed-off-by: Pin-yen Lin <[email protected]>
> > > ---
> > >
> > > Changes in v2:
> > > - Use mutex instead of the completion and autosuspend hack
> > >
> > > drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
> > > 1 file changed, 16 insertions(+)
> >
> > This looks OK to me now.
> >
> > Reviewed-by: Douglas Anderson <[email protected]>
> >
> > I'll let it stew on the mailing list for ~1 week and then land it in
> > drm-misc-fixes unless there are additional comments.
>
> Pushed to drm-misc-fixes:
>
> 26db46bc9c67 drm/bridge: parade-ps8640: Ensure bridge is suspended in
> .post_disable()
Crud. I landed this and then almost immediately hit a bug with it. :(
I've posted up the fix:
https://lore.kernel.org/r/20240117103502.1.Ib726a0184913925efc7e99c4d4fc801982e1bc24@changeid
-Doug
Hi Doug,
On Thu, Jan 18, 2024 at 2:37 AM Doug Anderson <[email protected]> wrote:
>
> Hi,
>
> On Wed, Jan 17, 2024 at 9:34 AM Doug Anderson <[email protected]> wrote:
> >
> > Hi,
> >
> > On Tue, Jan 9, 2024 at 8:52 AM Doug Anderson <dianders@chromiumorg> wrote:
> > >
> > > Hi,
> > >
> > > On Tue, Jan 9, 2024 at 4:05 AM Pin-yen Lin <[email protected]> wrote:
> > > >
> > > > The ps8640 bridge seems to expect everything to be power cycled at the
> > > > disable process, but sometimes ps8640_aux_transfer() holds the runtime
> > > > PM reference and prevents the bridge from suspend.
> > > >
> > > > Prevent that by introducing a mutex lock between ps8640_aux_transfer()
> > > > and .post_disable() to make sure the bridge is really powered off.
> > > >
> > > > Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
> > > > Signed-off-by: Pin-yen Lin <[email protected]>
> > > > ---
> > > >
> > > > Changes in v2:
> > > > - Use mutex instead of the completion and autosuspend hack
> > > >
> > > > drivers/gpu/drm/bridge/parade-ps8640.c | 16 ++++++++++++++++
> > > > 1 file changed, 16 insertions(+)
> > >
> > > This looks OK to me now.
> > >
> > > Reviewed-by: Douglas Anderson <[email protected]>
> > >
> > > I'll let it stew on the mailing list for ~1 week and then land it in
> > > drm-misc-fixes unless there are additional comments.
> >
> > Pushed to drm-misc-fixes:
> >
> > 26db46bc9c67 drm/bridge: parade-ps8640: Ensure bridge is suspended in
> > .post_disable()
>
> Crud. I landed this and then almost immediately hit a bug with it. :(
> I've posted up the fix:
>
> https://lore.kernel.org/r/20240117103502.1.Ib726a0184913925efc7e99c4d4fc801982e1bc24@changeid
>
> -Doug
Sorry, I missed this because the patch was based on drm-misc-next, so
it did not include commit 024b32db43a3 ("drm/bridge: parade-ps8640:
Wait for HPD when doing an AUX transfer").
I also forgot to apply that commit when I did my testing.
Pin-yen