diff options
| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-12-19 20:03:19 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-12-29 11:38:37 +0900 |
| commit | 9d43649a7740cf715c750929d19661a35144e7d1 (patch) | |
| tree | e3fc884c41a3f6f976ceadf10e69231deec8113a /drivers/mtd/nand/raw/denali.c | |
| parent | 8ccfbfb3e1c54caf67def3626ca046fafaa5092d (diff) | |
mtd: rawnand: denali: fix a race condition when DMA is kicked
Based on Linux commit cf51e4b9c34407bf0c3d9b582b7837e047e1df47
Add the register read-back, commenting why this is necessary.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'drivers/mtd/nand/raw/denali.c')
| -rw-r--r-- | drivers/mtd/nand/raw/denali.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c index bbfa3b6112..e0eb1339ec 100644 --- a/drivers/mtd/nand/raw/denali.c +++ b/drivers/mtd/nand/raw/denali.c @@ -587,6 +587,12 @@ static int denali_dma_xfer(struct denali_nand_info *denali, void *buf, } iowrite32(DMA_ENABLE__FLAG, denali->reg + DMA_ENABLE); + /* + * The ->setup_dma() hook kicks DMA by using the data/command + * interface, which belongs to a different AXI port from the + * register interface. Read back the register to avoid a race. + */ + ioread32(denali->reg + DMA_ENABLE); denali_reset_irq(denali); denali->setup_dma(denali, dma_addr, page, write); |