Currently if a DMA buffer straddles a buffer alignment boundary
(512KiB) then the DMA engine will pause and generate a DMA
interrupt. Since the DMA interrupt is not enabled it will hang
the MMC driver.
This patch adds support for restarting the DMA transfer. The
SYSTEM_ADDRESS register contains the next address that would have
been read/written when a boundary is hit. So we can read that
and write it back. The write triggers the resumption of the
transfer.
Signed-off-by: Anton Staaf <robot...@chromium.org>
Cc: Andy Fleming <aflem...@gmail.com>
Cc: Tom Warren <twar...@nvidia.com>
Cc: Stephen Warren <swar...@nvidia.com>
Cc: Albert Aribaud <albert.u.b...@aribaud.net>
---
drivers/mmc/tegra2_mmc.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/tegra2_mmc.c b/drivers/mmc/tegra2_mmc.c
index 2bea07d..159cef1 100644
--- a/drivers/mmc/tegra2_mmc.c
+++ b/drivers/mmc/tegra2_mmc.c
@@ -270,9 +270,16 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd
*cmd,
__func__, mask);
return -1;
} else if (mask & TEGRA_MMC_NORINTSTS_DMA_INTERRUPT) {
- /* DMA Interrupt */
+ /*
+ * DMA Interrupt, restart the transfer where
+ * it was interrupted.
+ */
+ unsigned int address = readl(&host->reg->sysad);
+
debug("DMA end\n");
- break;
+ writel(TEGRA_MMC_NORINTSTS_DMA_INTERRUPT,
+ &host->reg->norintsts);
+ writel(address, &host->reg->sysad);
} else if (mask & TEGRA_MMC_NORINTSTS_XFER_COMPLETE) {
/* Transfer Complete */
debug("r/w is done\n");
@@ -419,6 +426,7 @@ static int mmc_core_init(struct mmc *mmc)
* NORMAL Interrupt Status Enable Register init
* [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
* [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
+ * [3] ENSTADMAINT : DMA boundary interrupt
* [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
* [0] ENSTACMDCMPLT : Command Complete Status Enable
*/
@@ -426,6 +434,7 @@ static int mmc_core_init(struct mmc *mmc)
mask &= ~(0xffff);
mask |= (TEGRA_MMC_NORINTSTSEN_CMD_COMPLETE |
TEGRA_MMC_NORINTSTSEN_XFER_COMPLETE |
+ TEGRA_MMC_NORINTSTSEN_DMA_INTERRUPT |
TEGRA_MMC_NORINTSTSEN_BUFFER_WRITE_READY |
TEGRA_MMC_NORINTSTSEN_BUFFER_READ_READY);
writel(mask, &host->reg->norintstsen);
--
1.7.3.1
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
