[U-Boot] [PATCH v2] tegra: mmc: Support operation with dcache enabled

[U-Boot] [PATCH v2] tegra: mmc: Support operation with dcache enabled

[Simon Glass]

When the data cache is enabled we must flush on write and invalidate
on read. We also check that buffers are aligned to data cache lines
boundaries. With recent work in U-Boot this should generally be the case
but the warnings will catch problems.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
Changes in v2:
- Add casts to avoid compile warning

 drivers/mmc/tegra2_mmc.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/tegra2_mmc.c b/drivers/mmc/tegra2_mmc.c
index 035a868..17a988a 100644
--- a/drivers/mmc/tegra2_mmc.c
+++ b/drivers/mmc/tegra2_mmc.c
@@ -114,6 +114,14 @@ static void mmc_set_transfer_mode(struct mmc_host *host, struct mmc_data *data)
 	if (data->flags & MMC_DATA_READ)
 		mode |= TEGRA_MMC_TRNMOD_DATA_XFER_DIR_SEL_READ;
 
+	if (data->flags & MMC_DATA_WRITE) {
+		if ((uintptr_t)data->src & (ARCH_DMA_MINALIGN - 1))
+			printf("Warning: unaligned write to %p may fail\n",
+			       data->src);
+		flush_dcache_range((ulong)data->src, (ulong)data->src +
+			data->blocks * data->blocksize);
+	}
+
 	writew(mode, &host->reg->trnmod);
 }
 
@@ -310,6 +318,14 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 			}
 		}
 		writel(mask, &host->reg->norintsts);
+		if (data->flags & MMC_DATA_READ) {
+			if ((uintptr_t)data->dest & (ARCH_DMA_MINALIGN - 1))
+				printf("Warning: unaligned read from %p "
+					"may fail\n", data->dest);
+			invalidate_dcache_range((ulong)data->dest,
+				(ulong)data->dest +
+					data->blocks * data->blocksize);
+		}
 	}
 
 	udelay(1000);
-- 
1.7.3.1

[U-Boot] [PATCH v2] tegra: mmc: Support operation with dcache enabled

[Stephen Warren]

On 01/09/2012 04:20 PM, Simon Glass wrote:
> When the data cache is enabled we must flush on write and invalidate
> on read. We also check that buffers are aligned to data cache lines
> boundaries. With recent work in U-Boot this should generally be the case
> but the warnings will catch problems.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>

Seems reasonable to me.

Acked-by: Stephen Warren <swarren@nvidia.com>

-- 
nvpublic