[v1,01/12] fbdev: gxfb: use generic power management
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Message ID 20200805180722.244008-2-vaibhavgupta40@gmail.com
State New
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  • video: fbdev: use generic power management
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Commit Message

Vaibhav Gupta Aug. 5, 2020, 6:07 p.m. UTC
Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.

Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions, as through
the generic framework PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
---
 drivers/video/fbdev/geode/gxfb.h       |  5 ----
 drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
 drivers/video/fbdev/geode/suspend_gx.c |  4 ---
 3 files changed, 20 insertions(+), 25 deletions(-)

Comments

Sam Ravnborg Aug. 8, 2020, 11:17 a.m. UTC | #1
Hi Vaibhav

On Wed, Aug 05, 2020 at 11:37:11PM +0530, Vaibhav Gupta wrote:
> Drivers using legacy power management .suspen()/.resume() callbacks
> have to manage PCI states and device's PM states themselves. They also
> need to take care of standard configuration registers.
> 
> Switch to generic power management framework using a single
> "struct dev_pm_ops" variable

"to take the unnecessary load from the driver."
- I do not parse the above - I cannot see what load is removed.
But the code is simpler which is fine. The drawback is that we now
always link in the suspend_gx functions but hopefultl the linker drops
them later.

> This also avoids the need for the driver to directly call most of the PCI
> helper functions and device power state control functions, as through
> the generic framework PCI Core takes care of the necessary operations,
> and drivers are required to do only device-specific jobs.
Again, I do not see what calles are removed.
A single check for the state is dropped - anything else?

> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> ---
>  drivers/video/fbdev/geode/gxfb.h       |  5 ----
>  drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
>  drivers/video/fbdev/geode/suspend_gx.c |  4 ---
>  3 files changed, 20 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
> index d2e9c5c8e294..792c111c21e4 100644
> --- a/drivers/video/fbdev/geode/gxfb.h
> +++ b/drivers/video/fbdev/geode/gxfb.h
> @@ -21,7 +21,6 @@ struct gxfb_par {
>  	void __iomem *dc_regs;
>  	void __iomem *vid_regs;
>  	void __iomem *gp_regs;
> -#ifdef CONFIG_PM
>  	int powered_down;
>  
>  	/* register state, for power management functionality */
> @@ -36,7 +35,6 @@ struct gxfb_par {
>  	uint64_t fp[FP_REG_COUNT];
>  
>  	uint32_t pal[DC_PAL_COUNT];
> -#endif
>  };
>  
>  unsigned int gx_frame_buffer_size(void);
> @@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info);
>  void gx_configure_display(struct fb_info *info);
>  int gx_blank_display(struct fb_info *info, int blank_mode);
>  
> -#ifdef CONFIG_PM
>  int gx_powerdown(struct fb_info *info);
>  int gx_powerup(struct fb_info *info);
> -#endif
> -
>  
>  /* Graphics Processor registers (table 6-23 from the data book) */
>  enum gp_registers {
> diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
> index d38a148d4746..44089b331f91 100644
> --- a/drivers/video/fbdev/geode/gxfb_core.c
> +++ b/drivers/video/fbdev/geode/gxfb_core.c
> @@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev)
>  	return info;
>  }
>  
> -#ifdef CONFIG_PM
> -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused gxfb_suspend(struct device *dev)
>  {
> -	struct fb_info *info = pci_get_drvdata(pdev);
> +	struct fb_info *info = dev_get_drvdata(dev);
I do not see any dev_set_drvdata() so I guess we get a NULL pointer
here which is not intended.
Adding a dev_set_data() to gxfb_probe() would do the trick.

>  
> -	if (state.event == PM_EVENT_SUSPEND) {
> -		console_lock();
> -		gx_powerdown(info);
> -		fb_set_suspend(info, 1);
> -		console_unlock();
> -	}
> +	console_lock();
> +	gx_powerdown(info);
> +	fb_set_suspend(info, 1);
> +	console_unlock();
>  
>  	/* there's no point in setting PCI states; we emulate PCI, so
>  	 * we don't end up getting power savings anyways */
> @@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
>  	return 0;
>  }
>  
> -static int gxfb_resume(struct pci_dev *pdev)
> +static int __maybe_unused gxfb_resume(struct device *dev)
>  {
> -	struct fb_info *info = pci_get_drvdata(pdev);
> +	struct fb_info *info = dev_get_drvdata(dev);
>  	int ret;
>  
>  	console_lock();
> @@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev)
>  	console_unlock();
>  	return 0;
>  }
> -#endif
>  
>  static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  {
> @@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = {
>  
>  MODULE_DEVICE_TABLE(pci, gxfb_id_table);
>  
> +static const struct dev_pm_ops gxfb_pm_ops = {
> +#ifdef CONFIG_PM_SLEEP
> +	.suspend	= gxfb_suspend,
> +	.resume		= gxfb_resume,
> +	.freeze		= NULL,
> +	.thaw		= gxfb_resume,
> +	.poweroff	= NULL,
> +	.restore	= gxfb_resume,
> +#endif
> +};
Can we use SET_SYSTEM_SLEEP_PM_OPS here?
.freeze will be assigned gxfb_suspend, but gxfb_suspend will anyway be
called as far as I read the code.
Likewise for poweroff.

	Sam

> +
>  static struct pci_driver gxfb_driver = {
>  	.name		= "gxfb",
>  	.id_table	= gxfb_id_table,
>  	.probe		= gxfb_probe,
>  	.remove		= gxfb_remove,
> -#ifdef CONFIG_PM
> -	.suspend	= gxfb_suspend,
> -	.resume		= gxfb_resume,
> -#endif
> +	.driver.pm	= &gxfb_pm_ops,
>  };
>  
>  #ifndef MODULE
> diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
> index 1110a527c35c..8c49d4e98772 100644
> --- a/drivers/video/fbdev/geode/suspend_gx.c
> +++ b/drivers/video/fbdev/geode/suspend_gx.c
> @@ -11,8 +11,6 @@
>  
>  #include "gxfb.h"
>  
> -#ifdef CONFIG_PM
> -
>  static void gx_save_regs(struct gxfb_par *par)
>  {
>  	int i;
> @@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info)
>  	par->powered_down  = 0;
>  	return 0;
>  }
> -
> -#endif
> -- 
> 2.27.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Vaibhav Gupta Aug. 10, 2020, 9:39 a.m. UTC | #2
On Sat, Aug 08, 2020 at 01:17:46PM +0200, Sam Ravnborg wrote:
> Hi Vaibhav
> 
> On Wed, Aug 05, 2020 at 11:37:11PM +0530, Vaibhav Gupta wrote:
> > Drivers using legacy power management .suspen()/.resume() callbacks
> > have to manage PCI states and device's PM states themselves. They also
> > need to take care of standard configuration registers.
> > 
> > Switch to generic power management framework using a single
> > "struct dev_pm_ops" variable
> 
> "to take the unnecessary load from the driver."
> - I do not parse the above - I cannot see what load is removed.
> But the code is simpler which is fine. The drawback is that we now
> always link in the suspend_gx functions but hopefultl the linker drops
> them later.
> 
> > This also avoids the need for the driver to directly call most of the PCI
> > helper functions and device power state control functions, as through
> > the generic framework PCI Core takes care of the necessary operations,
> > and drivers are required to do only device-specific jobs.
> Again, I do not see what calles are removed.
> A single check for the state is dropped - anything else?
>
Yeah, the commit messages are bit misleading, I have modified them. 
> > 
> > Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> > ---
> >  drivers/video/fbdev/geode/gxfb.h       |  5 ----
> >  drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
> >  drivers/video/fbdev/geode/suspend_gx.c |  4 ---
> >  3 files changed, 20 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
> > index d2e9c5c8e294..792c111c21e4 100644
> > --- a/drivers/video/fbdev/geode/gxfb.h
> > +++ b/drivers/video/fbdev/geode/gxfb.h
> > @@ -21,7 +21,6 @@ struct gxfb_par {
> >  	void __iomem *dc_regs;
> >  	void __iomem *vid_regs;
> >  	void __iomem *gp_regs;
> > -#ifdef CONFIG_PM
> >  	int powered_down;
> >  
> >  	/* register state, for power management functionality */
> > @@ -36,7 +35,6 @@ struct gxfb_par {
> >  	uint64_t fp[FP_REG_COUNT];
> >  
> >  	uint32_t pal[DC_PAL_COUNT];
> > -#endif
> >  };
> >  
> >  unsigned int gx_frame_buffer_size(void);
> > @@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info);
> >  void gx_configure_display(struct fb_info *info);
> >  int gx_blank_display(struct fb_info *info, int blank_mode);
> >  
> > -#ifdef CONFIG_PM
> >  int gx_powerdown(struct fb_info *info);
> >  int gx_powerup(struct fb_info *info);
> > -#endif
> > -
> >  
> >  /* Graphics Processor registers (table 6-23 from the data book) */
> >  enum gp_registers {
> > diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
> > index d38a148d4746..44089b331f91 100644
> > --- a/drivers/video/fbdev/geode/gxfb_core.c
> > +++ b/drivers/video/fbdev/geode/gxfb_core.c
> > @@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev)
> >  	return info;
> >  }
> >  
> > -#ifdef CONFIG_PM
> > -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > +static int __maybe_unused gxfb_suspend(struct device *dev)
> >  {
> > -	struct fb_info *info = pci_get_drvdata(pdev);
> > +	struct fb_info *info = dev_get_drvdata(dev);
> I do not see any dev_set_drvdata() so I guess we get a NULL pointer
> here which is not intended.
> Adding a dev_set_data() to gxfb_probe() would do the trick.
> 
gxfb_probe() invokes pci_set_drvdata(pdev, info) which in turn calls
dev_set_drvdata(&pdev->dev, data). Adding dev_get_drvdata() will be redundant.

> >  
> > -	if (state.event == PM_EVENT_SUSPEND) {
> > -		console_lock();
> > -		gx_powerdown(info);
> > -		fb_set_suspend(info, 1);
> > -		console_unlock();
> > -	}
> > +	console_lock();
> > +	gx_powerdown(info);
> > +	fb_set_suspend(info, 1);
> > +	console_unlock();
> >  
> >  	/* there's no point in setting PCI states; we emulate PCI, so
> >  	 * we don't end up getting power savings anyways */
> > @@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> >  	return 0;
> >  }
> >  
> > -static int gxfb_resume(struct pci_dev *pdev)
> > +static int __maybe_unused gxfb_resume(struct device *dev)
> >  {
> > -	struct fb_info *info = pci_get_drvdata(pdev);
> > +	struct fb_info *info = dev_get_drvdata(dev);
> >  	int ret;
> >  
> >  	console_lock();
> > @@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev)
> >  	console_unlock();
> >  	return 0;
> >  }
> > -#endif
> >  
> >  static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >  {
> > @@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = {
> >  
> >  MODULE_DEVICE_TABLE(pci, gxfb_id_table);
> >  
> > +static const struct dev_pm_ops gxfb_pm_ops = {
> > +#ifdef CONFIG_PM_SLEEP
> > +	.suspend	= gxfb_suspend,
> > +	.resume		= gxfb_resume,
> > +	.freeze		= NULL,
> > +	.thaw		= gxfb_resume,
> > +	.poweroff	= NULL,
> > +	.restore	= gxfb_resume,
> > +#endif
> > +};
> Can we use SET_SYSTEM_SLEEP_PM_OPS here?
> .freeze will be assigned gxfb_suspend, but gxfb_suspend will anyway be
> called as far as I read the code.
> Likewise for poweroff.
> 
Earlier, gxfb_suspend() performed each operation just for suspend event.
And as it was legacy code, it was invoked by pci_legacy_suspend() for
pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff().
Thus, the code was wrapped inside "if" container:
	if (state.event == PM_EVENT_SUSPEND) { }

After binding it with dev_pm_ops variable, pm->suspend() is invoked by just
pci_pm_suspend() which is required.

So I removed the "if" container and bind the callback with pm->suspend pointer
only.

Using SET_SYSTEM_PM_OPS will bring back the extra step of invoking gxfb_suspend()
for freeze and poweroff, even though the function will do nothing in that case.

Vaibhav Gupta
> 	Sam
> 
> > +
> >  static struct pci_driver gxfb_driver = {
> >  	.name		= "gxfb",
> >  	.id_table	= gxfb_id_table,
> >  	.probe		= gxfb_probe,
> >  	.remove		= gxfb_remove,
> > -#ifdef CONFIG_PM
> > -	.suspend	= gxfb_suspend,
> > -	.resume		= gxfb_resume,
> > -#endif
> > +	.driver.pm	= &gxfb_pm_ops,
> >  };
> >  
> >  #ifndef MODULE
> > diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
> > index 1110a527c35c..8c49d4e98772 100644
> > --- a/drivers/video/fbdev/geode/suspend_gx.c
> > +++ b/drivers/video/fbdev/geode/suspend_gx.c
> > @@ -11,8 +11,6 @@
> >  
> >  #include "gxfb.h"
> >  
> > -#ifdef CONFIG_PM
> > -
> >  static void gx_save_regs(struct gxfb_par *par)
> >  {
> >  	int i;
> > @@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info)
> >  	par->powered_down  = 0;
> >  	return 0;
> >  }
> > -
> > -#endif
> > -- 
> > 2.27.0
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Vaibhav Gupta Aug. 10, 2020, 9:44 a.m. UTC | #3
> > > -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > > +static int __maybe_unused gxfb_suspend(struct device *dev)
> > >  {
> > > -	struct fb_info *info = pci_get_drvdata(pdev);
> > > +	struct fb_info *info = dev_get_drvdata(dev);
> > I do not see any dev_set_drvdata() so I guess we get a NULL pointer
> > here which is not intended.
> > Adding a dev_set_data() to gxfb_probe() would do the trick.
> > 
> gxfb_probe() invokes pci_set_drvdata(pdev, info) which in turn calls
> dev_set_drvdata(&pdev->dev, data). Adding dev_get_drvdata() will be redundant.
> 
s/dev_get_drvdata/dev_set_drvdata

Thanks
Vaibhav Gupta
Sam Ravnborg Aug. 10, 2020, 4:54 p.m. UTC | #4
Hi Vaibhav
On Mon, Aug 10, 2020 at 03:09:48PM +0530, Vaibhav Gupta wrote:
> On Sat, Aug 08, 2020 at 01:17:46PM +0200, Sam Ravnborg wrote:
> > Hi Vaibhav
> > 
> > On Wed, Aug 05, 2020 at 11:37:11PM +0530, Vaibhav Gupta wrote:
> > > Drivers using legacy power management .suspen()/.resume() callbacks
> > > have to manage PCI states and device's PM states themselves. They also
> > > need to take care of standard configuration registers.
> > > 
> > > Switch to generic power management framework using a single
> > > "struct dev_pm_ops" variable
> > 
> > "to take the unnecessary load from the driver."
> > - I do not parse the above - I cannot see what load is removed.
> > But the code is simpler which is fine. The drawback is that we now
> > always link in the suspend_gx functions but hopefultl the linker drops
> > them later.
> > 
> > > This also avoids the need for the driver to directly call most of the PCI
> > > helper functions and device power state control functions, as through
> > > the generic framework PCI Core takes care of the necessary operations,
> > > and drivers are required to do only device-specific jobs.
> > Again, I do not see what calles are removed.
> > A single check for the state is dropped - anything else?
> >
> Yeah, the commit messages are bit misleading, I have modified them. 
> > > 
> > > Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> > > ---
> > >  drivers/video/fbdev/geode/gxfb.h       |  5 ----
> > >  drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
> > >  drivers/video/fbdev/geode/suspend_gx.c |  4 ---
> > >  3 files changed, 20 insertions(+), 25 deletions(-)
> > > 
> > > diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
> > > index d2e9c5c8e294..792c111c21e4 100644
> > > --- a/drivers/video/fbdev/geode/gxfb.h
> > > +++ b/drivers/video/fbdev/geode/gxfb.h
> > > @@ -21,7 +21,6 @@ struct gxfb_par {
> > >  	void __iomem *dc_regs;
> > >  	void __iomem *vid_regs;
> > >  	void __iomem *gp_regs;
> > > -#ifdef CONFIG_PM
> > >  	int powered_down;
> > >  
> > >  	/* register state, for power management functionality */
> > > @@ -36,7 +35,6 @@ struct gxfb_par {
> > >  	uint64_t fp[FP_REG_COUNT];
> > >  
> > >  	uint32_t pal[DC_PAL_COUNT];
> > > -#endif
> > >  };
> > >  
> > >  unsigned int gx_frame_buffer_size(void);
> > > @@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info);
> > >  void gx_configure_display(struct fb_info *info);
> > >  int gx_blank_display(struct fb_info *info, int blank_mode);
> > >  
> > > -#ifdef CONFIG_PM
> > >  int gx_powerdown(struct fb_info *info);
> > >  int gx_powerup(struct fb_info *info);
> > > -#endif
> > > -
> > >  
> > >  /* Graphics Processor registers (table 6-23 from the data book) */
> > >  enum gp_registers {
> > > diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
> > > index d38a148d4746..44089b331f91 100644
> > > --- a/drivers/video/fbdev/geode/gxfb_core.c
> > > +++ b/drivers/video/fbdev/geode/gxfb_core.c
> > > @@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev)
> > >  	return info;
> > >  }
> > >  
> > > -#ifdef CONFIG_PM
> > > -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > > +static int __maybe_unused gxfb_suspend(struct device *dev)
> > >  {
> > > -	struct fb_info *info = pci_get_drvdata(pdev);
> > > +	struct fb_info *info = dev_get_drvdata(dev);
> > I do not see any dev_set_drvdata() so I guess we get a NULL pointer
> > here which is not intended.
> > Adding a dev_set_data() to gxfb_probe() would do the trick.
> > 
> gxfb_probe() invokes pci_set_drvdata(pdev, info) which in turn calls
> dev_set_drvdata(&pdev->dev, data). Adding dev_get_drvdata() will be redundant.
OK, not obvious but you are right that calling dev_get_drvdata() would
be redundant and no need.
There is a pci_get_drvdata() user left so we cannot just skip it and use
the dev_set_drvdata() direct.

> 
> > >  
> > > -	if (state.event == PM_EVENT_SUSPEND) {
> > > -		console_lock();
> > > -		gx_powerdown(info);
> > > -		fb_set_suspend(info, 1);
> > > -		console_unlock();
> > > -	}
> > > +	console_lock();
> > > +	gx_powerdown(info);
> > > +	fb_set_suspend(info, 1);
> > > +	console_unlock();
> > >  
> > >  	/* there's no point in setting PCI states; we emulate PCI, so
> > >  	 * we don't end up getting power savings anyways */
> > > @@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > >  	return 0;
> > >  }
> > >  
> > > -static int gxfb_resume(struct pci_dev *pdev)
> > > +static int __maybe_unused gxfb_resume(struct device *dev)
> > >  {
> > > -	struct fb_info *info = pci_get_drvdata(pdev);
> > > +	struct fb_info *info = dev_get_drvdata(dev);
> > >  	int ret;
> > >  
> > >  	console_lock();
> > > @@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev)
> > >  	console_unlock();
> > >  	return 0;
> > >  }
> > > -#endif
> > >  
> > >  static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> > >  {
> > > @@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = {
> > >  
> > >  MODULE_DEVICE_TABLE(pci, gxfb_id_table);
> > >  
> > > +static const struct dev_pm_ops gxfb_pm_ops = {
> > > +#ifdef CONFIG_PM_SLEEP
> > > +	.suspend	= gxfb_suspend,
> > > +	.resume		= gxfb_resume,
> > > +	.freeze		= NULL,
> > > +	.thaw		= gxfb_resume,
> > > +	.poweroff	= NULL,
> > > +	.restore	= gxfb_resume,
> > > +#endif
> > > +};
> > Can we use SET_SYSTEM_SLEEP_PM_OPS here?
> > .freeze will be assigned gxfb_suspend, but gxfb_suspend will anyway be
> > called as far as I read the code.
> > Likewise for poweroff.
> > 
> Earlier, gxfb_suspend() performed each operation just for suspend event.
> And as it was legacy code, it was invoked by pci_legacy_suspend() for
> pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff().
> Thus, the code was wrapped inside "if" container:
> 	if (state.event == PM_EVENT_SUSPEND) { }
> 
> After binding it with dev_pm_ops variable, pm->suspend() is invoked by just
> pci_pm_suspend() which is required.
> 
> So I removed the "if" container and bind the callback with pm->suspend pointer
> only.
Looking at platform.c I got the impression that freeze() would call
pci_legacy_suspend() anyway - but I may have missind something.
So I guess this is OK then.

I look forward for next revision with updated changelogs.

	Sam
> 
> Using SET_SYSTEM_PM_OPS will bring back the extra step of invoking gxfb_suspend()
> for freeze and poweroff, even though the function will do nothing in that case.
> 
> Vaibhav Gupta
> > 	Sam
> > 
> > > +
> > >  static struct pci_driver gxfb_driver = {
> > >  	.name		= "gxfb",
> > >  	.id_table	= gxfb_id_table,
> > >  	.probe		= gxfb_probe,
> > >  	.remove		= gxfb_remove,
> > > -#ifdef CONFIG_PM
> > > -	.suspend	= gxfb_suspend,
> > > -	.resume		= gxfb_resume,
> > > -#endif
> > > +	.driver.pm	= &gxfb_pm_ops,
> > >  };
> > >  
> > >  #ifndef MODULE
> > > diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
> > > index 1110a527c35c..8c49d4e98772 100644
> > > --- a/drivers/video/fbdev/geode/suspend_gx.c
> > > +++ b/drivers/video/fbdev/geode/suspend_gx.c
> > > @@ -11,8 +11,6 @@
> > >  
> > >  #include "gxfb.h"
> > >  
> > > -#ifdef CONFIG_PM
> > > -
> > >  static void gx_save_regs(struct gxfb_par *par)
> > >  {
> > >  	int i;
> > > @@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info)
> > >  	par->powered_down  = 0;
> > >  	return 0;
> > >  }
> > > -
> > > -#endif
> > > -- 
> > > 2.27.0
> > > 
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Vaibhav Gupta Aug. 10, 2020, 5:58 p.m. UTC | #5
On Mon, Aug 10, 2020 at 06:54:58PM +0200, Sam Ravnborg wrote:
> Hi Vaibhav
> On Mon, Aug 10, 2020 at 03:09:48PM +0530, Vaibhav Gupta wrote:
> > On Sat, Aug 08, 2020 at 01:17:46PM +0200, Sam Ravnborg wrote:
> > > Hi Vaibhav
> > > 
> > > On Wed, Aug 05, 2020 at 11:37:11PM +0530, Vaibhav Gupta wrote:
> > > > Drivers using legacy power management .suspen()/.resume() callbacks
> > > > have to manage PCI states and device's PM states themselves. They also
> > > > need to take care of standard configuration registers.
> > > > 
> > > > Switch to generic power management framework using a single
> > > > "struct dev_pm_ops" variable
> > > 
> > > "to take the unnecessary load from the driver."
> > > - I do not parse the above - I cannot see what load is removed.
> > > But the code is simpler which is fine. The drawback is that we now
> > > always link in the suspend_gx functions but hopefultl the linker drops
> > > them later.
> > > 
> > > > This also avoids the need for the driver to directly call most of the PCI
> > > > helper functions and device power state control functions, as through
> > > > the generic framework PCI Core takes care of the necessary operations,
> > > > and drivers are required to do only device-specific jobs.
> > > Again, I do not see what calles are removed.
> > > A single check for the state is dropped - anything else?
> > >
> > Yeah, the commit messages are bit misleading, I have modified them. 
> > > > 
> > > > Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> > > > ---
> > > >  drivers/video/fbdev/geode/gxfb.h       |  5 ----
> > > >  drivers/video/fbdev/geode/gxfb_core.c  | 36 ++++++++++++++------------
> > > >  drivers/video/fbdev/geode/suspend_gx.c |  4 ---
> > > >  3 files changed, 20 insertions(+), 25 deletions(-)
> > > > 
> > > > diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
> > > > index d2e9c5c8e294..792c111c21e4 100644
> > > > --- a/drivers/video/fbdev/geode/gxfb.h
> > > > +++ b/drivers/video/fbdev/geode/gxfb.h
> > > > @@ -21,7 +21,6 @@ struct gxfb_par {
> > > >  	void __iomem *dc_regs;
> > > >  	void __iomem *vid_regs;
> > > >  	void __iomem *gp_regs;
> > > > -#ifdef CONFIG_PM
> > > >  	int powered_down;
> > > >  
> > > >  	/* register state, for power management functionality */
> > > > @@ -36,7 +35,6 @@ struct gxfb_par {
> > > >  	uint64_t fp[FP_REG_COUNT];
> > > >  
> > > >  	uint32_t pal[DC_PAL_COUNT];
> > > > -#endif
> > > >  };
> > > >  
> > > >  unsigned int gx_frame_buffer_size(void);
> > > > @@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info);
> > > >  void gx_configure_display(struct fb_info *info);
> > > >  int gx_blank_display(struct fb_info *info, int blank_mode);
> > > >  
> > > > -#ifdef CONFIG_PM
> > > >  int gx_powerdown(struct fb_info *info);
> > > >  int gx_powerup(struct fb_info *info);
> > > > -#endif
> > > > -
> > > >  
> > > >  /* Graphics Processor registers (table 6-23 from the data book) */
> > > >  enum gp_registers {
> > > > diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
> > > > index d38a148d4746..44089b331f91 100644
> > > > --- a/drivers/video/fbdev/geode/gxfb_core.c
> > > > +++ b/drivers/video/fbdev/geode/gxfb_core.c
> > > > @@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev)
> > > >  	return info;
> > > >  }
> > > >  
> > > > -#ifdef CONFIG_PM
> > > > -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > > > +static int __maybe_unused gxfb_suspend(struct device *dev)
> > > >  {
> > > > -	struct fb_info *info = pci_get_drvdata(pdev);
> > > > +	struct fb_info *info = dev_get_drvdata(dev);
> > > I do not see any dev_set_drvdata() so I guess we get a NULL pointer
> > > here which is not intended.
> > > Adding a dev_set_data() to gxfb_probe() would do the trick.
> > > 
> > gxfb_probe() invokes pci_set_drvdata(pdev, info) which in turn calls
> > dev_set_drvdata(&pdev->dev, data). Adding dev_get_drvdata() will be redundant.
> OK, not obvious but you are right that calling dev_get_drvdata() would
> be redundant and no need.
> There is a pci_get_drvdata() user left so we cannot just skip it and use
> the dev_set_drvdata() direct.
> 
> > 
> > > >  
> > > > -	if (state.event == PM_EVENT_SUSPEND) {
> > > > -		console_lock();
> > > > -		gx_powerdown(info);
> > > > -		fb_set_suspend(info, 1);
> > > > -		console_unlock();
> > > > -	}
> > > > +	console_lock();
> > > > +	gx_powerdown(info);
> > > > +	fb_set_suspend(info, 1);
> > > > +	console_unlock();
> > > >  
> > > >  	/* there's no point in setting PCI states; we emulate PCI, so
> > > >  	 * we don't end up getting power savings anyways */
> > > > @@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
> > > >  	return 0;
> > > >  }
> > > >  
> > > > -static int gxfb_resume(struct pci_dev *pdev)
> > > > +static int __maybe_unused gxfb_resume(struct device *dev)
> > > >  {
> > > > -	struct fb_info *info = pci_get_drvdata(pdev);
> > > > +	struct fb_info *info = dev_get_drvdata(dev);
> > > >  	int ret;
> > > >  
> > > >  	console_lock();
> > > > @@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev)
> > > >  	console_unlock();
> > > >  	return 0;
> > > >  }
> > > > -#endif
> > > >  
> > > >  static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> > > >  {
> > > > @@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = {
> > > >  
> > > >  MODULE_DEVICE_TABLE(pci, gxfb_id_table);
> > > >  
> > > > +static const struct dev_pm_ops gxfb_pm_ops = {
> > > > +#ifdef CONFIG_PM_SLEEP
> > > > +	.suspend	= gxfb_suspend,
> > > > +	.resume		= gxfb_resume,
> > > > +	.freeze		= NULL,
> > > > +	.thaw		= gxfb_resume,
> > > > +	.poweroff	= NULL,
> > > > +	.restore	= gxfb_resume,
> > > > +#endif
> > > > +};
> > > Can we use SET_SYSTEM_SLEEP_PM_OPS here?
> > > .freeze will be assigned gxfb_suspend, but gxfb_suspend will anyway be
> > > called as far as I read the code.
> > > Likewise for poweroff.
> > > 
> > Earlier, gxfb_suspend() performed each operation just for suspend event.
> > And as it was legacy code, it was invoked by pci_legacy_suspend() for
> > pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff().
> > Thus, the code was wrapped inside "if" container:
> > 	if (state.event == PM_EVENT_SUSPEND) { }
> > 
> > After binding it with dev_pm_ops variable, pm->suspend() is invoked by just
> > pci_pm_suspend() which is required.
> > 
> > So I removed the "if" container and bind the callback with pm->suspend pointer
> > only.
> Looking at platform.c I got the impression that freeze() would call
> pci_legacy_suspend() anyway - but I may have missind something.
> So I guess this is OK then.
> 
> I look forward for next revision with updated changelogs.
Hello Sam,

Yeah, I have updated the logs, will be sending the v2 soon. :)

Thanks
Vaibhav Gupta
> 
> 	Sam
> > 
> > Using SET_SYSTEM_PM_OPS will bring back the extra step of invoking gxfb_suspend()
> > for freeze and poweroff, even though the function will do nothing in that case.
> > 
> > Vaibhav Gupta
> > > 	Sam
> > > 
> > > > +
> > > >  static struct pci_driver gxfb_driver = {
> > > >  	.name		= "gxfb",
> > > >  	.id_table	= gxfb_id_table,
> > > >  	.probe		= gxfb_probe,
> > > >  	.remove		= gxfb_remove,
> > > > -#ifdef CONFIG_PM
> > > > -	.suspend	= gxfb_suspend,
> > > > -	.resume		= gxfb_resume,
> > > > -#endif
> > > > +	.driver.pm	= &gxfb_pm_ops,
> > > >  };
> > > >  
> > > >  #ifndef MODULE
> > > > diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
> > > > index 1110a527c35c..8c49d4e98772 100644
> > > > --- a/drivers/video/fbdev/geode/suspend_gx.c
> > > > +++ b/drivers/video/fbdev/geode/suspend_gx.c
> > > > @@ -11,8 +11,6 @@
> > > >  
> > > >  #include "gxfb.h"
> > > >  
> > > > -#ifdef CONFIG_PM
> > > > -
> > > >  static void gx_save_regs(struct gxfb_par *par)
> > > >  {
> > > >  	int i;
> > > > @@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info)
> > > >  	par->powered_down  = 0;
> > > >  	return 0;
> > > >  }
> > > > -
> > > > -#endif
> > > > -- 
> > > > 2.27.0
> > > > 
> > > > _______________________________________________
> > > > dri-devel mailing list
> > > > dri-devel@lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Vaibhav Gupta Aug. 10, 2020, 6:57 p.m. UTC | #6
Linux Kernel Mentee: Remove Legacy Power Management.

The purpose of this patch series is to upgrade power management in video fbdev
drivers. This has been done by upgrading .suspend() and .resume() callbacks.

The upgrade makes sure that the involvement of PCI Core does not change the
order of operations executed in a driver. Thus, does not change its behavior.

In general, drivers with legacy PM, .suspend() and .resume() make use of PCI
helper functions like pci_enable/disable_device_mem(), pci_set_power_state(),
pci_save/restore_state(), pci_enable/disable_device(), etc. to complete
their job.

The conversion requires the removal of those function calls, change the
callbacks' definition accordingly and make use of dev_pm_ops structure.

All patches are compile-tested only.

Test tools:
    - Compiler: gcc (GCC) 10.1.0
    - allmodconfig build: make -j$(nproc) W=1 all

Vaibhav Gupta (12):
  fbdev: gxfb: use generic power management
  fbdev: lxfb: use generic power management
  fbdev: via-core: use generic power management
  fbdev: aty: use generic power management
  fbdev: aty128fb: use generic power management
  fbdev: nvidia: use generic power management
  fbdev: savagefb: use generic power management
  fbdev: cyber2000fb: use generic power management
  fbdev: i740fb: use generic power management
  fbdev: vt8623fb: use generic power management
  fbdev: s3fb: use generic power management
  fbdev: arkfb: use generic power management

 drivers/video/fbdev/arkfb.c                  | 41 ++++++-------
 drivers/video/fbdev/aty/aty128fb.c           | 51 ++++++++++------
 drivers/video/fbdev/aty/atyfb_base.c         | 50 ++++++++++-----
 drivers/video/fbdev/cyber2000fb.c            | 13 ++--
 drivers/video/fbdev/geode/gxfb.h             |  5 --
 drivers/video/fbdev/geode/gxfb_core.c        | 36 ++++++-----
 drivers/video/fbdev/geode/lxfb.h             |  5 --
 drivers/video/fbdev/geode/lxfb_core.c        | 37 +++++------
 drivers/video/fbdev/geode/lxfb_ops.c         |  4 --
 drivers/video/fbdev/geode/suspend_gx.c       |  4 --
 drivers/video/fbdev/i740fb.c                 | 40 +++++-------
 drivers/video/fbdev/nvidia/nvidia.c          | 64 +++++++++++---------
 drivers/video/fbdev/s3fb.c                   | 39 +++++-------
 drivers/video/fbdev/savage/savagefb_driver.c | 52 ++++++++++------
 drivers/video/fbdev/via/via-core.c           | 39 +++++-------
 drivers/video/fbdev/vt8623fb.c               | 41 ++++++-------
 include/linux/via-core.h                     |  2 -
 17 files changed, 267 insertions(+), 256 deletions(-)

Patch
diff mbox series

diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h
index d2e9c5c8e294..792c111c21e4 100644
--- a/drivers/video/fbdev/geode/gxfb.h
+++ b/drivers/video/fbdev/geode/gxfb.h
@@ -21,7 +21,6 @@  struct gxfb_par {
 	void __iomem *dc_regs;
 	void __iomem *vid_regs;
 	void __iomem *gp_regs;
-#ifdef CONFIG_PM
 	int powered_down;
 
 	/* register state, for power management functionality */
@@ -36,7 +35,6 @@  struct gxfb_par {
 	uint64_t fp[FP_REG_COUNT];
 
 	uint32_t pal[DC_PAL_COUNT];
-#endif
 };
 
 unsigned int gx_frame_buffer_size(void);
@@ -49,11 +47,8 @@  void gx_set_dclk_frequency(struct fb_info *info);
 void gx_configure_display(struct fb_info *info);
 int gx_blank_display(struct fb_info *info, int blank_mode);
 
-#ifdef CONFIG_PM
 int gx_powerdown(struct fb_info *info);
 int gx_powerup(struct fb_info *info);
-#endif
-
 
 /* Graphics Processor registers (table 6-23 from the data book) */
 enum gp_registers {
diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
index d38a148d4746..44089b331f91 100644
--- a/drivers/video/fbdev/geode/gxfb_core.c
+++ b/drivers/video/fbdev/geode/gxfb_core.c
@@ -322,17 +322,14 @@  static struct fb_info *gxfb_init_fbinfo(struct device *dev)
 	return info;
 }
 
-#ifdef CONFIG_PM
-static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused gxfb_suspend(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 
-	if (state.event == PM_EVENT_SUSPEND) {
-		console_lock();
-		gx_powerdown(info);
-		fb_set_suspend(info, 1);
-		console_unlock();
-	}
+	console_lock();
+	gx_powerdown(info);
+	fb_set_suspend(info, 1);
+	console_unlock();
 
 	/* there's no point in setting PCI states; we emulate PCI, so
 	 * we don't end up getting power savings anyways */
@@ -340,9 +337,9 @@  static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int gxfb_resume(struct pci_dev *pdev)
+static int __maybe_unused gxfb_resume(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	int ret;
 
 	console_lock();
@@ -356,7 +353,6 @@  static int gxfb_resume(struct pci_dev *pdev)
 	console_unlock();
 	return 0;
 }
-#endif
 
 static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -467,15 +463,23 @@  static const struct pci_device_id gxfb_id_table[] = {
 
 MODULE_DEVICE_TABLE(pci, gxfb_id_table);
 
+static const struct dev_pm_ops gxfb_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= gxfb_suspend,
+	.resume		= gxfb_resume,
+	.freeze		= NULL,
+	.thaw		= gxfb_resume,
+	.poweroff	= NULL,
+	.restore	= gxfb_resume,
+#endif
+};
+
 static struct pci_driver gxfb_driver = {
 	.name		= "gxfb",
 	.id_table	= gxfb_id_table,
 	.probe		= gxfb_probe,
 	.remove		= gxfb_remove,
-#ifdef CONFIG_PM
-	.suspend	= gxfb_suspend,
-	.resume		= gxfb_resume,
-#endif
+	.driver.pm	= &gxfb_pm_ops,
 };
 
 #ifndef MODULE
diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c
index 1110a527c35c..8c49d4e98772 100644
--- a/drivers/video/fbdev/geode/suspend_gx.c
+++ b/drivers/video/fbdev/geode/suspend_gx.c
@@ -11,8 +11,6 @@ 
 
 #include "gxfb.h"
 
-#ifdef CONFIG_PM
-
 static void gx_save_regs(struct gxfb_par *par)
 {
 	int i;
@@ -259,5 +257,3 @@  int gx_powerup(struct fb_info *info)
 	par->powered_down  = 0;
 	return 0;
 }
-
-#endif