Hi, On 16-12-14 01:37, David Lanzendörfer wrote:
When there is only one DES available the DMA performs a FIFO reset and waits until the reinitialization has been completed. Disabling the SDXC_IDMAC_DES0_DIC bit prevents the DMA from sending an interrupt after it has finished this reinitialization. The flags SDXC_IDMAC_DES0_FD and SDXC_IDMAC_DES0_LD are both required in order to use the controller with more than one DES. Signed-off-by: David Lanzendörfer <david.lanzendoerfer@xxxxxx> Reported-by: 李想 <lixiang@xxxxxxxxxxxxxxxxx> --- drivers/mmc/host/sunxi-mmc.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c index 50bd3d2..5331c88 100644 --- a/drivers/mmc/host/sunxi-mmc.c +++ b/drivers/mmc/host/sunxi-mmc.c @@ -310,7 +310,17 @@ static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host, } pdes[0].config |= SDXC_IDMAC_DES0_FD; - pdes[i - 1].config = SDXC_IDMAC_DES0_OWN | SDXC_IDMAC_DES0_LD; + + /* + * When there is only one DES available the DMA performs a FIFO reset and waits + * until the reinitialization has been completed. + * Disabling the SDXC_IDMAC_DES0_DIC bit prevents the DMA from sending an interrupt + * after it has finished this reinitialization. + */ + pdes[i - 1].config = SDXC_IDMAC_DES0_OWN; + pdes[i - 1].config |= SDXC_IDMAC_DES0_FD; + pdes[i - 1].config |= SDXC_IDMAC_DES0_LD; + pdes[i - 1].config &= ~SDXC_IDMAC_DES0_DIC; /* * Avoid the io-store starting the idmac hitting io-mem before the
This is wrong. For one you are starting with an assignment, so you could just as well set all the flags you want with a single line / assignment. Besides that you're setting the FD flag, which should only be set for the first descriptor of a transfer, so for multi descriptor transfers this is wrong. Please see the patch which I send you which gets this right. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
