Re: [PATCH] mmc: sunxi-mmc: Fix DMA descriptors allocated above 32 bits

From: Jernej Škrabec
Date: Mon Apr 25 2022 - 11:38:44 EST


Dne ponedeljek, 25. april 2022 ob 01:17:50 CEST je Samuel Holland napisal(a):
> Newer variants of the MMC controller support a 34-bit physical address
> space by using word addresses instead of byte addresses. However, the
> code truncates the DMA descriptor address to 32 bits before applying the
> shift. This breaks DMA for descriptors allocated above the 32-bit limit.
>
> Fixes: 3536b82e5853 ("mmc: sunxi: add support for A100 mmc controller")
> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>

Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>

Best regards,
Jernej

> ---
>
> drivers/mmc/host/sunxi-mmc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
> index c62afd212692..46f9e2923d86 100644
> --- a/drivers/mmc/host/sunxi-mmc.c
> +++ b/drivers/mmc/host/sunxi-mmc.c
> @@ -377,8 +377,9 @@ static void sunxi_mmc_init_idma_des(struct
sunxi_mmc_host *host,
> pdes[i].buf_addr_ptr1 =
> cpu_to_le32(sg_dma_address(&data->sg[i]) >>
> host->cfg->idma_des_shift);
> - pdes[i].buf_addr_ptr2 = cpu_to_le32((u32)next_desc >>
> - host-
>cfg->idma_des_shift);
> + pdes[i].buf_addr_ptr2 =
> + cpu_to_le32(next_desc >>
> + host->cfg->idma_des_shift);
> }
>
> pdes[0].config |= cpu_to_le32(SDXC_IDMAC_DES0_FD);
> --
> 2.35.1
>
>