On Mon, Aug 09, 2021 at 04:31:46PM +0300, Imre Deak wrote: > Atm the EFI FB platform driver gets a runtime PM reference for the > associated GFX PCI device during probing the EFI FB platform device and > releases it only when the platform device gets unbound. > > When fbcon switches to the FB provided by the PCI device's driver (for > instance i915/drmfb), the EFI FB will get only unregistered without the > EFI FB platform device getting unbound, keeping the runtime PM reference > acquired during the platform device probing. This reference will prevent > the PCI driver from runtime suspending the device. > > Fix this by releasing the RPM reference from the EFI FB's destroy hook, > called when the FB gets unregistered. > > While at it assert that pm_runtime_get_sync() didn't fail. > > v2: > - Move pm_runtime_get_sync() before register_framebuffer() to avoid its > race wrt. efifb_destroy()->pm_runtime_put(). (Daniel) > - Assert that pm_runtime_get_sync() didn't fail. > - Clarify commit message wrt. platform/PCI device/driver and driver > removal vs. device unbinding. > > Fixes: a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") > Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> (v1) > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> Thanks for the reviews, pushed to drm-intel-next. > --- > drivers/video/fbdev/efifb.c | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c > index 8ea8f079cde26..edca3703b9640 100644 > --- a/drivers/video/fbdev/efifb.c > +++ b/drivers/video/fbdev/efifb.c > @@ -47,6 +47,8 @@ static bool use_bgrt = true; > static bool request_mem_succeeded = false; > static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC; > > +static struct pci_dev *efifb_pci_dev; /* dev with BAR covering the efifb */ > + > static struct fb_var_screeninfo efifb_defined = { > .activate = FB_ACTIVATE_NOW, > .height = -1, > @@ -243,6 +245,9 @@ static inline void efifb_show_boot_graphics(struct fb_info *info) {} > > static void efifb_destroy(struct fb_info *info) > { > + if (efifb_pci_dev) > + pm_runtime_put(&efifb_pci_dev->dev); > + > if (info->screen_base) { > if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC)) > iounmap(info->screen_base); > @@ -333,7 +338,6 @@ ATTRIBUTE_GROUPS(efifb); > > static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */ > > -static struct pci_dev *efifb_pci_dev; /* dev with BAR covering the efifb */ > static struct resource *bar_resource; > static u64 bar_offset; > > @@ -569,17 +573,22 @@ static int efifb_probe(struct platform_device *dev) > pr_err("efifb: cannot allocate colormap\n"); > goto err_groups; > } > + > + if (efifb_pci_dev) > + WARN_ON(pm_runtime_get_sync(&efifb_pci_dev->dev) < 0); > + > err = register_framebuffer(info); > if (err < 0) { > pr_err("efifb: cannot register framebuffer\n"); > - goto err_fb_dealoc; > + goto err_put_rpm_ref; > } > fb_info(info, "%s frame buffer device\n", info->fix.id); > - if (efifb_pci_dev) > - pm_runtime_get_sync(&efifb_pci_dev->dev); > return 0; > > -err_fb_dealoc: > +err_put_rpm_ref: > + if (efifb_pci_dev) > + pm_runtime_put(&efifb_pci_dev->dev); > + > fb_dealloc_cmap(&info->cmap); > err_groups: > sysfs_remove_groups(&dev->dev.kobj, efifb_groups); > @@ -603,8 +612,6 @@ static int efifb_remove(struct platform_device *pdev) > unregister_framebuffer(info); > sysfs_remove_groups(&pdev->dev.kobj, efifb_groups); > framebuffer_release(info); > - if (efifb_pci_dev) > - pm_runtime_put(&efifb_pci_dev->dev); > > return 0; > } > -- > 2.27.0 >