| Message ID | 20210809133146.2478382-1-imre.deak@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] fbdev/efifb: Release PCI device's runtime PM ref during FB destroy | expand |
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@canonical.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1) > Signed-off-by: Imre Deak <imre.deak@intel.com> 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 >
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; }
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@canonical.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1) Signed-off-by: Imre Deak <imre.deak@intel.com> --- drivers/video/fbdev/efifb.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)