On 5/24/19 5:31 AM, Shuah Khan wrote: > media_device is embedded in struct vimc_device and when vimc is removed > vimc_device and the embedded media_device goes with it, while the active > stream and vimc_capture continue to access it. > > Fix the media_device lifetime problem by changing vimc to create shared > media_device using Media Device Allocator API and vimc_capture getting > a reference to vimc module. With this change, vimc module can be removed > only when the references are gone. vimc can be removed after vimc_capture > is removed. > > Media Device Allocator API supports just USB devices. Enhance it > adding a genetic device allocate interface to support other media > drivers. > > The new interface takes pointer to struct device instead and creates > media device. This interface allows a group of drivers that have a > common root device to share media device resource and ensure media > device doesn't get deleted as long as one of the drivers holds its > reference. > > The new interface has been tested with vimc component driver to fix > panics when vimc module is removed while streaming is in progress. Helen, can you review this series? I'm not sure this is the right approach for a driver like vimc, and even if it is, then it is odd that vimc-capture is the only vimc module that's handled here. My gut feeling is that this should be handled inside vimc directly and not using the media-dev-allocator. Regards, Hans > > Shuah Khan (2): > media: add generic device allocate interface to media-dev-allocator > vimc: fix BUG: unable to handle kernel NULL pointer dereference > > drivers/media/Makefile | 4 +- > drivers/media/media-dev-allocator.c | 39 ++++++++++++++ > drivers/media/platform/vimc/vimc-capture.c | 17 +++++- > drivers/media/platform/vimc/vimc-core.c | 60 ++++++++++++---------- > include/media/media-dev-allocator.h | 46 ++++++++++++++--- > 5 files changed, 130 insertions(+), 36 deletions(-) >
