Hi Am 02.11.20 um 13:09 schrieb Thomas Zimmermann: > Hi > > Am 02.11.20 um 12:19 schrieb Tian Tao: >> Add the detection of false for irq, so that the EINVAL is not >> returned when dev->irq_enabled is false. >> >> Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx> >> --- >> drivers/gpu/drm/drm_irq.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c >> index 09d6e9e..7537a3d 100644 >> --- a/drivers/gpu/drm/drm_irq.c >> +++ b/drivers/gpu/drm/drm_irq.c >> @@ -172,6 +172,9 @@ int drm_irq_uninstall(struct drm_device *dev) >> bool irq_enabled; >> int i; >> >> + if (!dev->irq_enabled || !dev) >> + return 0; >> + > > Dereferencing a pointer before NULL-checking it, is Yoda programming. :) > I'd just drop the test for !dev and assume that dev is always valid. > > I suggest to change the int return value to void and return nothing. > > Re-reading the actual implementation of this function, this location > might be too early. Further below there already is a test for > irq_enabled. Put a drm_WARN_ON around it and it should be fine. This way > the vblank handlers will be disabled and erroneous callers will see a > warning in the kernel's log. In addition to these changes, you could also add a managed implementation of drm_irq_install(). The canonical name should be devm_drm_irq_install(). The function would call drm_irq_install() and register a cleanup handler via devm_add_action(). Example code is at [1]. KMS drivers, such as hibmc, would then not have to bother about uninstalling the DRM irq. Best regards Thomas [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/drm_drv.c#n664 > > Best regards > Thomas > >> irq_enabled = dev->irq_enabled; >> dev->irq_enabled = false; >> >> > > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel > -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer
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