| Message ID | 20201228122131.138454-1-ezequiel@collabora.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] media: imx: Unregister csc/scaler only if registered | expand |
Hi Ezequiel, On Mon, 2020-12-28 at 09:21 -0300, Ezequiel Garcia wrote: > The csc/scaler device pointer (imxmd->m2m_vdev) is assigned > after the imx media device v4l2-async probe completes, > therefore we need to check if the device is non-NULL > before trying to unregister it. > > This can be the case if the non-completed imx media device > is unbinded (or the driver is removed), leading to a kernel oops. > > Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> > --- > drivers/staging/media/imx/imx-media-dev.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c > index 6d2205461e56..b6d5f844ad79 100644 > --- a/drivers/staging/media/imx/imx-media-dev.c > +++ b/drivers/staging/media/imx/imx-media-dev.c > @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev) > > v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n"); > > + if (imxmd->m2m_vdev) { Thank you, it's even worse. If imx_media_csc_scaler_device_init() fails in imx6_media_probe_complete(), imxmd->m2m_vdev contains an error value. So either this should check if (!IS_ERR_OR_NULL(imxmd->m2m_vdev)) or (probably better) probe_complete should be changed as well. > + imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); > + imxmd->m2m_vdev = NULL; > + } > + > v4l2_async_notifier_unregister(&imxmd->notifier); > imx_media_unregister_ipu_internal_subdevs(imxmd); > v4l2_async_notifier_cleanup(&imxmd->notifier); > - imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); > media_device_unregister(&imxmd->md); > v4l2_device_unregister(&imxmd->v4l2_dev); > media_device_cleanup(&imxmd->md); regards Philipp
Hello Philipp, Thanks for the quick review. On Mon, 2021-01-04 at 18:16 +0100, Philipp Zabel wrote: > Hi Ezequiel, > > On Mon, 2020-12-28 at 09:21 -0300, Ezequiel Garcia wrote: > > The csc/scaler device pointer (imxmd->m2m_vdev) is assigned > > after the imx media device v4l2-async probe completes, > > therefore we need to check if the device is non-NULL > > before trying to unregister it. > > > > This can be the case if the non-completed imx media device > > is unbinded (or the driver is removed), leading to a kernel oops. > > > > Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") > > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> > > --- > > drivers/staging/media/imx/imx-media-dev.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c > > index 6d2205461e56..b6d5f844ad79 100644 > > --- a/drivers/staging/media/imx/imx-media-dev.c > > +++ b/drivers/staging/media/imx/imx-media-dev.c > > @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev) > > > > v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n"); > > > > + if (imxmd->m2m_vdev) { > > Thank you, it's even worse. If imx_media_csc_scaler_device_init() fails > in imx6_media_probe_complete(), imxmd->m2m_vdev contains an error value. > > So either this should check > > if (!IS_ERR_OR_NULL(imxmd->m2m_vdev)) > > or (probably better) probe_complete should be changed as well. > Good catch. I guess the simplest solution for that is to clear the m2m_vdev pointer in imx6_media_probe_complete, if it fails. Thanks, Ezequiel
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c index 6d2205461e56..b6d5f844ad79 100644 --- a/drivers/staging/media/imx/imx-media-dev.c +++ b/drivers/staging/media/imx/imx-media-dev.c @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev) v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n"); + if (imxmd->m2m_vdev) { + imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); + imxmd->m2m_vdev = NULL; + } + v4l2_async_notifier_unregister(&imxmd->notifier); imx_media_unregister_ipu_internal_subdevs(imxmd); v4l2_async_notifier_cleanup(&imxmd->notifier); - imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev); media_device_unregister(&imxmd->md); v4l2_device_unregister(&imxmd->v4l2_dev); media_device_cleanup(&imxmd->md);
The csc/scaler device pointer (imxmd->m2m_vdev) is assigned after the imx media device v4l2-async probe completes, therefore we need to check if the device is non-NULL before trying to unregister it. This can be the case if the non-completed imx media device is unbinded (or the driver is removed), leading to a kernel oops. Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> --- drivers/staging/media/imx/imx-media-dev.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)