Hi Vaibhav

On Tue, Aug 11, 2020 at 12:27:12AM +0530, Vaibhav Gupta wrote:
> Drivers should do only device-specific jobs. But in general, drivers using
> legacy PCI PM framework for .suspend()/.resume() have to manage many PCI
> PM-related tasks themselves which can be done by PCI Core itself. This
> brings extra load on the driver and it directly calls PCI helper functions
> to handle them.
> 
> Although the gxfb driver does not have that extra load,
Sorry, but I am lost here.
If this drivers does not have the extra load that you describe here then
I really cannot see why it is relevant for this driver to describe it.

This is a seldomly touched driver - so it helps if the changelog when we
finally touch the code is easy to parse.

> we should switch to
> the new generic framework by updating function signatures and define a
> "struct dev_pm_ops" variable to bind PM callbacks so that we can remove
> the legacy .suspend & .resume bindings.
This part matches the patch - good.

> Additionally, this helps us to
> remove the unnecessary call to gxfb_suspend() in the event of Freeze and
> Hibernate, as the function does nothing in their case.
What I think you are explaining above is that the pci pm support
will only call the suspend operation in case of suspend, so the 
state.event == PM_EVENT_SUSPEND can be dropped in gxfb_suspend().

For reference later I would prefer that this is explained a bit
more explicit - not that the changelog needs update anyway.
> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupt...@gmail.com>
Patch looks good, but please give the changelog one more go.
I have not checked other patches - but I assume they would benefit
from a similar clarification.

        Sam

> ---
>  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);
>  
> -     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
> -- 
> 2.27.0
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to