On Tue, Jun 09, 2026 at 01:08:33PM +0000, Gustavo Kenji Mendonça Kaneko wrote: > komeda_dev_resume() calls clk_prepare_enable() without checking the > return value. If the clock fails to enable, the function returns 0 > (success) while IRQs are enabled and IOMMU is connected on potentially > unclocked hardware, causing undefined behavior on resume. > > Propagate the error from clk_prepare_enable() and fix all call sites > in komeda_drv.c that previously ignored the return value of > komeda_dev_resume(): > > - komeda_platform_probe(): if resume fails, jump to err_destroy_mdev > (skipping the suspend call, since the clock was never enabled) > - komeda_pm_resume(): propagate the error and skip > drm_mode_config_helper_resume() on failure > > This issue was found by code review without access to Komeda hardware. > > Signed-off-by: Gustavo Kenji Mendonça Kaneko <[email protected]>
Reviewed-by: Liviu Dudau <[email protected]> Best regards, Liviu > --- > Changes in v2: > - Fix all call sites in komeda_drv.c that ignored the return value of > komeda_dev_resume() (Liviu Dudau) > - In komeda_platform_probe(), use a new err_destroy_mdev label to skip > the komeda_dev_suspend() call when resume itself failed > - In komeda_pm_resume(), propagate the error from komeda_dev_resume() > and skip drm_mode_config_helper_resume() on failure > > drivers/gpu/drm/arm/display/komeda/komeda_dev.c | 6 +++++- > drivers/gpu/drm/arm/display/komeda/komeda_drv.c | 14 +++++++++----- > 2 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > index 5ba62e637a61..9aad1d1d28ec 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > @@ -313,7 +313,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev) > > int komeda_dev_resume(struct komeda_dev *mdev) > { > - clk_prepare_enable(mdev->aclk); > + int err; > + > + err = clk_prepare_enable(mdev->aclk); > + if (err) > + return err; > > mdev->funcs->enable_irq(mdev); > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > index 4bb5f250e95e..67fffab018ae 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > @@ -74,8 +74,11 @@ static int komeda_platform_probe(struct platform_device > *pdev) > } > > pm_runtime_enable(dev); > - if (!pm_runtime_enabled(dev)) > - komeda_dev_resume(mdrv->mdev); > + if (!pm_runtime_enabled(dev)) { > + err = komeda_dev_resume(mdrv->mdev); > + if (err) > + goto err_destroy_mdev; > + } > > mdrv->kms = komeda_kms_attach(mdrv->mdev); > if (IS_ERR(mdrv->kms)) { > @@ -93,7 +96,7 @@ static int komeda_platform_probe(struct platform_device > *pdev) > pm_runtime_disable(dev); > else > komeda_dev_suspend(mdrv->mdev); > - > +err_destroy_mdev: > komeda_dev_destroy(mdrv->mdev); > > free_mdrv: > @@ -140,11 +143,12 @@ static int __maybe_unused komeda_pm_suspend(struct > device *dev) > static int __maybe_unused komeda_pm_resume(struct device *dev) > { > struct komeda_drv *mdrv = dev_get_drvdata(dev); > + int err = 0; > > if (!pm_runtime_status_suspended(dev)) > - komeda_dev_resume(mdrv->mdev); > + err = komeda_dev_resume(mdrv->mdev); > > - return drm_mode_config_helper_resume(&mdrv->kms->base); > + return err ? err : drm_mode_config_helper_resume(&mdrv->kms->base); > } > > static const struct dev_pm_ops komeda_pm_ops = { > -- > 2.54.0 > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯
