On Sun, May 31, 2026 at 05:30:02AM +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 return early on > failure to prevent hardware access without a valid clock. > > This issue was found by code review without access to Komeda hardware.
Hello, There is nothing wrong with the content of this patch, but I would like if anyone wants to fix these kind of problems to at least be thorough. komeda_dev_suspend() is also ignoring the errors coming from clk_disable_unprepare() and both fuctions before this patch always return 0, so in komeda_drv.c we can sometimes ignore the return value. If we add an extended version of this patch then we should also do proper error handling in komeda_drv.c Best regards, Liviu > > Signed-off-by: Gustavo Kenji Mendonça Kaneko <[email protected]> > --- > drivers/gpu/drm/arm/display/komeda/komeda_dev.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > 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); > > -- > 2.54.0 > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯
