On Mon, 18 Mar 2024 12:18:53 +0000 Robin Murphy <robin.murphy@xxxxxxx> wrote: > On 18/03/2024 8:58 am, Boris Brezillon wrote: > > Putting a hard dependency on CONFIG_PM is not possible because of a > > circular dependency issue, and it's actually not desirable either. In > > order to support this use case, we forcibly resume at init time, and > > suspend at unplug time. > > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Closes: https://lore.kernel.org/oe-kbuild-all/202403031944.EOimQ8WK-lkp@xxxxxxxxx/ > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > > --- > > Tested by faking CONFIG_PM=n in the driver (basically commenting > > all pm_runtime calls, and making the panthor_device_suspend/resume() > > calls unconditional in the panthor_device_unplug/init() path) since > > CONFIG_ARCH_ROCKCHIP selects CONFIG_PM. Seems to work fine, but I > > can't be 100% sure this will work correctly on a platform that has > > CONFIG_PM=n. > > --- > > drivers/gpu/drm/panthor/panthor_device.c | 13 +++++++++++-- > > drivers/gpu/drm/panthor/panthor_drv.c | 4 +++- > > 2 files changed, 14 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c > > index 69deb8e17778..ba7aedbb4931 100644 > > --- a/drivers/gpu/drm/panthor/panthor_device.c > > +++ b/drivers/gpu/drm/panthor/panthor_device.c > > @@ -87,6 +87,10 @@ void panthor_device_unplug(struct panthor_device *ptdev) > > pm_runtime_dont_use_autosuspend(ptdev->base.dev); > > pm_runtime_put_sync_suspend(ptdev->base.dev); > > > > + /* If PM is disabled, we need to call the suspend handler manually. */ > > + if (!IS_ENABLED(CONFIG_PM)) > > + panthor_device_suspend(ptdev->base.dev); > > + > > /* Report the unplug operation as done to unblock concurrent > > * panthor_device_unplug() callers. > > */ > > @@ -218,6 +222,13 @@ int panthor_device_init(struct panthor_device *ptdev) > > if (ret) > > return ret; > > > > + /* If PM is disabled, we need to call panthor_device_resume() manually. */ > > + if (!IS_ENABLED(CONFIG_PM)) { > > + ret = panthor_device_resume(ptdev->base.dev); > > + if (ret) > > + return ret; > > + } > > + > > ret = panthor_gpu_init(ptdev); > > if (ret) > > goto err_rpm_put; > > @@ -402,7 +413,6 @@ int panthor_device_mmap_io(struct panthor_device *ptdev, struct vm_area_struct * > > return 0; > > } > > > > -#ifdef CONFIG_PM > > int panthor_device_resume(struct device *dev) > > { > > struct panthor_device *ptdev = dev_get_drvdata(dev); > > @@ -547,4 +557,3 @@ int panthor_device_suspend(struct device *dev) > > mutex_unlock(&ptdev->pm.mmio_lock); > > return ret; > > } > > -#endif > > diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c > > index ff484506229f..2ea6a9f436db 100644 > > --- a/drivers/gpu/drm/panthor/panthor_drv.c > > +++ b/drivers/gpu/drm/panthor/panthor_drv.c > > @@ -1407,17 +1407,19 @@ static const struct of_device_id dt_match[] = { > > }; > > MODULE_DEVICE_TABLE(of, dt_match); > > > > +#ifdef CONFIG_PM > > This #ifdef isn't necessary, and in fact will break the !PM build - > pm_ptr() already takes care of allowing the compiler to optimise out the > ops structure itself without any further annotations. Oops, I forgot how pm_ptr() was working (I thought it had 2 definitions, one for the PM case and another for the !PM one). > > Thanks, > Robin. > > > static DEFINE_RUNTIME_DEV_PM_OPS(panthor_pm_ops, > > panthor_device_suspend, > > panthor_device_resume, > > NULL); > > +#endif > > > > static struct platform_driver panthor_driver = { > > .probe = panthor_probe, > > .remove_new = panthor_remove, > > .driver = { > > .name = "panthor", > > - .pm = &panthor_pm_ops, > > + .pm = pm_ptr(&panthor_pm_ops), > > .of_match_table = dt_match, > > }, > > };
