[PATCH 3/4] mmc: sunxi: Reset behavior fix
From: David LanzendÃrfer
Date: Mon Dec 15 2014 - 19:44:50 EST
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 LanzendÃrfer <david.lanzendoerfer@xxxxxx>
Reported-by: ææ <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
@@ -310,7 +310,17 @@ static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
pdes.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
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