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https://github.com/brain-hackers/u-boot-brain
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![]() This patch try to avoids eviction of dirty lines during DMA transfer. The code right now execute the following step: - allocate the buffer - start a dma operation using the non-coherent dma buffer - invalidate cache lines associated with the buffer - read the buffer This can lead to reading back not valid information, because the cache controller could evict dirty cache lines belonging to the buffer *after* the DMA operation has started to fill the DRAM. In order to avoid this, a new invalidation is required *before* starting the DMA operation. The patch just adds an invalidation before submitting the DMA command. Example below shows the nvme disk scan result without the following patch => nvme scan nvme_get_info_from_identify: nn = 544502629, vwc = 100, sn = dev_0T, mn = `�\�, fr = t_part, mdts = 105 So, invalidating the cache before submitting the admin command, fix the cpu read. Cc: André Przywara <andre.przywara@arm.com> Reported-by: Suniel Mahesh <sunil@amarulasolutions.com> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> Tested-by: Suniel Mahesh <sunil@amarulasolutions.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> |
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.. | ||
Kconfig | ||
Makefile | ||
nvme_show.c | ||
nvme-uclass.c | ||
nvme.c | ||
nvme.h |