Messages in this thread Patch in this message | | | Subject | [PATCH 3/4] mmc: sunxi: Reset behavior fix | From | David Lanzendörfer <> | Date | Tue, 16 Dec 2014 01:37:56 +0100 |
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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@o2s.ch> Reported-by: 李想 <lixiang@allwinnertech.com> --- 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
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