[PATCH] mmc: tmio: Check INFO1 for completion during DMA transfer

[Paul Barker]

On 20/02/2024 08:38, Marek Vasut wrote:
> In case a CRC error occurs during DMA transfer, the transfer completion
> flag is not set in TMIO_SD_DMA_INFO1 and the transfer would eventually
> time out. The timeout could be very long in case the transfer consists
> of a large amount of blocks, the base timeout is 10 seconds and every
> block adds 100 us more.
> 
> In case a CRC error does occur, a completion flag is set in a different
> register, TMIO_SD_INFO1. Use this other completion flag to detect DMA
> transfer ended and stop waiting for TMIO_SD_DMA_INFO1 completion flag.
> This reduces the lengthy timeout in case of an error. The unconditional
> check of TMIO_SD_DMA_INFO2 register for DMA related errors must not be
> skipped in any case to actually recognize the DMA error and report it.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> ---
> Cc: Hai Pham <hai.pham.ud at renesas.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Nobuhiro Iwamatsu <iwamatsu at nigauri.org>
> Cc: Paul Barker <paul.barker.ct at bp.renesas.com>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Sean Anderson <seanga2 at gmail.com>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
> ---
>  drivers/mmc/tmio-common.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/tmio-common.c b/drivers/mmc/tmio-common.c
> index 890c496b535..719c4830bc3 100644
> --- a/drivers/mmc/tmio-common.c
> +++ b/drivers/mmc/tmio-common.c
> @@ -299,7 +299,13 @@ static int tmio_sd_dma_wait_for_irq(struct udevice *dev, u32 flag,
>  	struct tmio_sd_priv *priv = dev_get_priv(dev);
>  	long wait = 1000000 + 10 * blocks;
>  
> -	while (!(tmio_sd_readl(priv, TMIO_SD_DMA_INFO1) & flag)) {
> +	for (;;) {
> +		if (tmio_sd_readl(priv, TMIO_SD_DMA_INFO1) & flag)
> +			break;
> +
> +		if (tmio_sd_readl(priv, TMIO_SD_INFO1) & TMIO_SD_INFO1_CMP)
> +			break;
> +
>  		if (wait-- < 0) {
>  			dev_err(dev, "timeout during DMA\n");
>  			return -ETIMEDOUT;

Reviewed-by: Paul Barker <paul.barker.ct at bp.renesas.com>
Tested-by: Paul Barker <paul.barker.ct at bp.renesas.com>
  (tested on RZ/G2L with commit ad50a8151387 from
  https://source.denx.de/u-boot/custodians/u-boot-sh)

-- 
Paul Barker
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