forked from luck/tmp_suning_uos_patched
f6ad0a4813
The problem can be easily reproduced using a script that loops copying a file in an SD card to another place in the same SD card and its related to read transfers. This only happens with DMA enabled. This is related to the fact that, when reading, an MMC irq signals the fact that all data from the SD card has been copied to the internal buffers. However, it doesn't signal whether the DMA transfer that is in charge of moving data from these internal buffers to RAM has finished or not. Thus, calling dmaengine_terminate_all() in the MMC irq routine can cancel an ongoing DMA transfer leaving some data in the internal buffers that produces an accumulative effect which, in the end, blocks a read data transfer forever. The following patch watches DMA irq for reading and MMC irqs for writing transfers. The 'dangerous' usage of dmaengine_terminate_all() is removed and a timeout of 10 seconds is added so that the MMC won't block forever anymore. Signed-off-by: Javier Martin <javier.martin@vista-silicon.com> Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Chris Ball <cjb@laptop.org> |
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