| Message ID | 20231117111433.1561669-7-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Small Runtime PM API changes | expand |
Hi Sakari, Thank you for the patch. On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > the device, in which case it won't increment the use count. > pm_runtime_put() does that unconditionally however. Only call > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > 0. Why don't you use pm_runtime_get_if_active() ? Other than that, same comment as for patch 5/7, I don't like the increased complexity. These comments apply to 7/7 as well. > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > --- > drivers/media/i2c/imx319.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > index 5378f607f340..e7b2d0c20d29 100644 > --- a/drivers/media/i2c/imx319.c > +++ b/drivers/media/i2c/imx319.c > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > struct imx319 *imx319 = container_of(ctrl->handler, > struct imx319, ctrl_handler); > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > + int ret, pm_status; > s64 max; > - int ret; > > /* Propagate change of current control to all related controls */ > switch (ctrl->id) { > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > * Applying V4L2 control value only happens > * when power is up for streaming > */ > - if (!pm_runtime_get_if_in_use(&client->dev)) > + pm_status = pm_runtime_get_if_in_use(&client->dev); > + if (!pm_status) > return 0; > > switch (ctrl->id) { > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > break; > } > > - pm_runtime_put(&client->dev); > + if (pm_status > 0) > + pm_runtime_put(&client->dev); > > return ret; > }
Hi Laurent, On Sat, Nov 18, 2023 at 08:52:48PM +0200, Laurent Pinchart wrote: > Hi Sakari, > > Thank you for the patch. > > On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > > the device, in which case it won't increment the use count. > > pm_runtime_put() does that unconditionally however. Only call > > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > > 0. > > Why don't you use pm_runtime_get_if_active() ? It's only meaningful if the driver uses autosuspend. The imx319 driver does not. > > Other than that, same comment as for patch 5/7, I don't like the > increased complexity. > > These comments apply to 7/7 as well. > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > --- > > drivers/media/i2c/imx319.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > > index 5378f607f340..e7b2d0c20d29 100644 > > --- a/drivers/media/i2c/imx319.c > > +++ b/drivers/media/i2c/imx319.c > > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > struct imx319 *imx319 = container_of(ctrl->handler, > > struct imx319, ctrl_handler); > > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > > + int ret, pm_status; > > s64 max; > > - int ret; > > > > /* Propagate change of current control to all related controls */ > > switch (ctrl->id) { > > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > * Applying V4L2 control value only happens > > * when power is up for streaming > > */ > > - if (!pm_runtime_get_if_in_use(&client->dev)) > > + pm_status = pm_runtime_get_if_in_use(&client->dev); > > + if (!pm_status) > > return 0; > > > > switch (ctrl->id) { > > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > break; > > } > > > > - pm_runtime_put(&client->dev); > > + if (pm_status > 0) > > + pm_runtime_put(&client->dev); > > > > return ret; > > } >
On Mon, Nov 20, 2023 at 09:32:10AM +0000, Sakari Ailus wrote: > On Sat, Nov 18, 2023 at 08:52:48PM +0200, Laurent Pinchart wrote: > > On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > > > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > > > the device, in which case it won't increment the use count. > > > pm_runtime_put() does that unconditionally however. Only call > > > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > > > 0. > > > > Why don't you use pm_runtime_get_if_active() ? > > It's only meaningful if the driver uses autosuspend. The imx319 driver does > not. Does pm_runtime_get_if_active() causes issues with the driver uses autosuspend ? Standardizing on a single API that covers all the use cases would increase consistency and make the code base easier to understand. Beside, the driver should switch to autosuspend :-) Using the correct RPM calls already is a good thing, if they don't introduce any issue. > > Other than that, same comment as for patch 5/7, I don't like the > > increased complexity. > > > > These comments apply to 7/7 as well. > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > --- > > > drivers/media/i2c/imx319.c | 8 +++++--- > > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > > > index 5378f607f340..e7b2d0c20d29 100644 > > > --- a/drivers/media/i2c/imx319.c > > > +++ b/drivers/media/i2c/imx319.c > > > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > struct imx319 *imx319 = container_of(ctrl->handler, > > > struct imx319, ctrl_handler); > > > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > > > + int ret, pm_status; > > > s64 max; > > > - int ret; > > > > > > /* Propagate change of current control to all related controls */ > > > switch (ctrl->id) { > > > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > * Applying V4L2 control value only happens > > > * when power is up for streaming > > > */ > > > - if (!pm_runtime_get_if_in_use(&client->dev)) > > > + pm_status = pm_runtime_get_if_in_use(&client->dev); > > > + if (!pm_status) > > > return 0; > > > > > > switch (ctrl->id) { > > > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > break; > > > } > > > > > > - pm_runtime_put(&client->dev); > > > + if (pm_status > 0) > > > + pm_runtime_put(&client->dev); > > > > > > return ret; > > > }
Hi Laurent, On Mon, Nov 20, 2023 at 11:45:03AM +0200, Laurent Pinchart wrote: > On Mon, Nov 20, 2023 at 09:32:10AM +0000, Sakari Ailus wrote: > > On Sat, Nov 18, 2023 at 08:52:48PM +0200, Laurent Pinchart wrote: > > > On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > > > > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > > > > the device, in which case it won't increment the use count. > > > > pm_runtime_put() does that unconditionally however. Only call > > > > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > > > > 0. > > > > > > Why don't you use pm_runtime_get_if_active() ? > > > > It's only meaningful if the driver uses autosuspend. The imx319 driver does > > not. > > Does pm_runtime_get_if_active() causes issues with the driver uses > autosuspend ? Standardizing on a single API that covers all the use > cases would increase consistency and make the code base easier to > understand. Beside, the driver should switch to autosuspend :-) Using > the correct RPM calls already is a good thing, if they don't introduce > any issue. Both are fine but they're there for a different purpose. The driver should consistently use either usage_count or status based calls (for autosuspend to make sense). > > > > Other than that, same comment as for patch 5/7, I don't like the > > > increased complexity. > > > > > > These comments apply to 7/7 as well. > > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > > --- > > > > drivers/media/i2c/imx319.c | 8 +++++--- > > > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > > > > index 5378f607f340..e7b2d0c20d29 100644 > > > > --- a/drivers/media/i2c/imx319.c > > > > +++ b/drivers/media/i2c/imx319.c > > > > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > struct imx319 *imx319 = container_of(ctrl->handler, > > > > struct imx319, ctrl_handler); > > > > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > > > > + int ret, pm_status; > > > > s64 max; > > > > - int ret; > > > > > > > > /* Propagate change of current control to all related controls */ > > > > switch (ctrl->id) { > > > > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > * Applying V4L2 control value only happens > > > > * when power is up for streaming > > > > */ > > > > - if (!pm_runtime_get_if_in_use(&client->dev)) > > > > + pm_status = pm_runtime_get_if_in_use(&client->dev); > > > > + if (!pm_status) > > > > return 0; > > > > > > > > switch (ctrl->id) { > > > > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > break; > > > > } > > > > > > > > - pm_runtime_put(&client->dev); > > > > + if (pm_status > 0) > > > > + pm_runtime_put(&client->dev); > > > > > > > > return ret; > > > > } >
On Tue, Nov 21, 2023 at 08:18:24AM +0000, Sakari Ailus wrote: > Hi Laurent, > > On Mon, Nov 20, 2023 at 11:45:03AM +0200, Laurent Pinchart wrote: > > On Mon, Nov 20, 2023 at 09:32:10AM +0000, Sakari Ailus wrote: > > > On Sat, Nov 18, 2023 at 08:52:48PM +0200, Laurent Pinchart wrote: > > > > On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > > > > > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > > > > > the device, in which case it won't increment the use count. > > > > > pm_runtime_put() does that unconditionally however. Only call > > > > > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > > > > > 0. > > > > > > > > Why don't you use pm_runtime_get_if_active() ? > > > > > > It's only meaningful if the driver uses autosuspend. The imx319 driver does > > > not. > > > > Does pm_runtime_get_if_active() causes issues with the driver uses > > autosuspend ? Standardizing on a single API that covers all the use > > cases would increase consistency and make the code base easier to > > understand. Beside, the driver should switch to autosuspend :-) Using > > the correct RPM calls already is a good thing, if they don't introduce > > any issue. > > Both are fine but they're there for a different purpose. The driver should > consistently use either usage_count or status based calls (for autosuspend > to make sense). But what's the drawback of using pm_runtime_get_if_active() in all cases (for camera sensor drivers) ? The semantics in the .s_ctrl() handler is "I want to proceed only if the device is powered on", and that's exactly what pm_runtime_get_if_active() gives us. The semantics of using pm_runtime_get_if_in_use() is "I want to proceed if someone else is holding a reference". It happens to give the same practical result as pm_runtime_get_if_active() when not using autosuspend, but it's still not the right semantics. > > > > Other than that, same comment as for patch 5/7, I don't like the > > > > increased complexity. > > > > > > > > These comments apply to 7/7 as well. > > > > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > > > --- > > > > > drivers/media/i2c/imx319.c | 8 +++++--- > > > > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > > > > > > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > > > > > index 5378f607f340..e7b2d0c20d29 100644 > > > > > --- a/drivers/media/i2c/imx319.c > > > > > +++ b/drivers/media/i2c/imx319.c > > > > > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > struct imx319 *imx319 = container_of(ctrl->handler, > > > > > struct imx319, ctrl_handler); > > > > > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > > > > > + int ret, pm_status; > > > > > s64 max; > > > > > - int ret; > > > > > > > > > > /* Propagate change of current control to all related controls */ > > > > > switch (ctrl->id) { > > > > > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > * Applying V4L2 control value only happens > > > > > * when power is up for streaming > > > > > */ > > > > > - if (!pm_runtime_get_if_in_use(&client->dev)) > > > > > + pm_status = pm_runtime_get_if_in_use(&client->dev); > > > > > + if (!pm_status) > > > > > return 0; > > > > > > > > > > switch (ctrl->id) { > > > > > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > break; > > > > > } > > > > > > > > > > - pm_runtime_put(&client->dev); > > > > > + if (pm_status > 0) > > > > > + pm_runtime_put(&client->dev); > > > > > > > > > > return ret; > > > > > }
Hi Laurent, On Tue, Nov 21, 2023 at 10:25:35AM +0200, Laurent Pinchart wrote: > On Tue, Nov 21, 2023 at 08:18:24AM +0000, Sakari Ailus wrote: > > Hi Laurent, > > > > On Mon, Nov 20, 2023 at 11:45:03AM +0200, Laurent Pinchart wrote: > > > On Mon, Nov 20, 2023 at 09:32:10AM +0000, Sakari Ailus wrote: > > > > On Sat, Nov 18, 2023 at 08:52:48PM +0200, Laurent Pinchart wrote: > > > > > On Fri, Nov 17, 2023 at 01:14:32PM +0200, Sakari Ailus wrote: > > > > > > pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for > > > > > > the device, in which case it won't increment the use count. > > > > > > pm_runtime_put() does that unconditionally however. Only call > > > > > > pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > > > > > > > 0. > > > > > > > > > > Why don't you use pm_runtime_get_if_active() ? > > > > > > > > It's only meaningful if the driver uses autosuspend. The imx319 driver does > > > > not. > > > > > > Does pm_runtime_get_if_active() causes issues with the driver uses > > > autosuspend ? Standardizing on a single API that covers all the use > > > cases would increase consistency and make the code base easier to > > > understand. Beside, the driver should switch to autosuspend :-) Using > > > the correct RPM calls already is a good thing, if they don't introduce > > > any issue. > > > > Both are fine but they're there for a different purpose. The driver should > > consistently use either usage_count or status based calls (for autosuspend > > to make sense). > > But what's the drawback of using pm_runtime_get_if_active() in all cases > (for camera sensor drivers) ? The semantics in the .s_ctrl() handler is > "I want to proceed only if the device is powered on", and that's exactly > what pm_runtime_get_if_active() gives us. The semantics of using > pm_runtime_get_if_in_use() is "I want to proceed if someone else is > holding a reference". It happens to give the same practical result as > pm_runtime_get_if_active() when not using autosuspend, but it's still > not the right semantics. Well, using the _active() variant here may introduce an unneeded write operation so that isn't actually an issue. But using the _if_in_use() variant in a driver using autosuspend may lead to missing a write --- as it returns 0 if the usage_count is 0 even if the device is in active state. Oh well. I can change the driver to use autosuspend but I think I'll split the set into two, one doing the Runtime PM API changes and another to address issues in sensor drivers. > > > > > > Other than that, same comment as for patch 5/7, I don't like the > > > > > increased complexity. > > > > > > > > > > These comments apply to 7/7 as well. > > > > > > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > > > > --- > > > > > > drivers/media/i2c/imx319.c | 8 +++++--- > > > > > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > > > > > > > > > diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c > > > > > > index 5378f607f340..e7b2d0c20d29 100644 > > > > > > --- a/drivers/media/i2c/imx319.c > > > > > > +++ b/drivers/media/i2c/imx319.c > > > > > > @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > > struct imx319 *imx319 = container_of(ctrl->handler, > > > > > > struct imx319, ctrl_handler); > > > > > > struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); > > > > > > + int ret, pm_status; > > > > > > s64 max; > > > > > > - int ret; > > > > > > > > > > > > /* Propagate change of current control to all related controls */ > > > > > > switch (ctrl->id) { > > > > > > @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > > * Applying V4L2 control value only happens > > > > > > * when power is up for streaming > > > > > > */ > > > > > > - if (!pm_runtime_get_if_in_use(&client->dev)) > > > > > > + pm_status = pm_runtime_get_if_in_use(&client->dev); > > > > > > + if (!pm_status) > > > > > > return 0; > > > > > > > > > > > > switch (ctrl->id) { > > > > > > @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) > > > > > > break; > > > > > > } > > > > > > > > > > > > - pm_runtime_put(&client->dev); > > > > > > + if (pm_status > 0) > > > > > > + pm_runtime_put(&client->dev); > > > > > > > > > > > > return ret; > > > > > > } >
diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c index 5378f607f340..e7b2d0c20d29 100644 --- a/drivers/media/i2c/imx319.c +++ b/drivers/media/i2c/imx319.c @@ -1880,8 +1880,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) struct imx319 *imx319 = container_of(ctrl->handler, struct imx319, ctrl_handler); struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); + int ret, pm_status; s64 max; - int ret; /* Propagate change of current control to all related controls */ switch (ctrl->id) { @@ -1898,7 +1898,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) * Applying V4L2 control value only happens * when power is up for streaming */ - if (!pm_runtime_get_if_in_use(&client->dev)) + pm_status = pm_runtime_get_if_in_use(&client->dev); + if (!pm_status) return 0; switch (ctrl->id) { @@ -1937,7 +1938,8 @@ static int imx319_set_ctrl(struct v4l2_ctrl *ctrl) break; } - pm_runtime_put(&client->dev); + if (pm_status > 0) + pm_runtime_put(&client->dev); return ret; }
pm_runtime_get_if_in_use() returns an error if Runtime PM is disabled for the device, in which case it won't increment the use count. pm_runtime_put() does that unconditionally however. Only call pm_runtime_put() in case pm_runtime_get_if_in_use() has returned a value > 0. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> --- drivers/media/i2c/imx319.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)