From 4683b220655937e8f3c360f4aa25274abed76e0d Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Thu, 25 Jun 2015 10:32:26 +0800 Subject: [PATCH] mmc:fsl_esdhc invalidate dcache before read DCIMVAC is upgraded to DCCIMVAC for the individual processor (Cortex-A7) that the DCIMVAC is executed on. We should follow the linux dma follow. Before DMA read, first invalidate dcache then after DMA read, invalidate dcache again. With the DMA direction DMA_FROM_DEVICE, the dcache need be invalidated again after the DMA completion. The reason is that we need explicity make sure the dcache been invalidated thus to get the DMA'ed memory correctly from the physical memory. Any cache-line fill during the DMA operations such as the pre-fetching can cause the DMA coherency issue, thus CPU get the stale data. Signed-off-by: Peng Fan Signed-off-by: Ye.Li Signed-off-by: Nitin Garg Signed-off-by: Jason Liu Reviewed-by: Stefano Babic --- drivers/mmc/fsl_esdhc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index c4719e6f36..0510bf02f4 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -341,6 +341,9 @@ esdhc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data) err = esdhc_setup_data(mmc, data); if(err) return err; + + if (data->flags & MMC_DATA_READ) + check_and_invalidate_dcache_range(cmd, data); } /* Figure out the transfer arguments */ @@ -437,6 +440,11 @@ esdhc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data) } } while ((irqstat & DATA_COMPLETE) != DATA_COMPLETE); + /* + * Need invalidate the dcache here again to avoid any + * cache-fill during the DMA operations such as the + * speculative pre-fetching etc. + */ if (data->flags & MMC_DATA_READ) check_and_invalidate_dcache_range(cmd, data); #endif -- 2.39.5