From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peng Fan Date: Fri, 10 Jul 2015 08:21:38 +0800 Subject: [U-Boot] [PATCH] mmc:fsl_esdhc invalidate dcache before read In-Reply-To: <1435199546-12292-1-git-send-email-Peng.Fan@freescale.com> References: <1435199546-12292-1-git-send-email-Peng.Fan@freescale.com> Message-ID: <20150710002136.GA8978@shlinux2> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Ping. Anyone review/apply this patch? On Thu, Jun 25, 2015 at 10:32:26AM +0800, Peng Fan wrote: >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 >--- > 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 c4719e6..0510bf0 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 >-- >1.8.4 > > >_______________________________________________ >U-Boot mailing list >U-Boot at lists.denx.de >http://lists.denx.de/mailman/listinfo/u-boot Regards, Peng. --