[PATCH] mmc: dwmmc: only clear handled interrupts

[Jerome Forissier]

On 9/15/22 19:56, John Keeping wrote:
> Unconditionally clearing DTO when RXDR is set leads to spurious timeouts
> in FIFO mode transfers if events occur in the following order:
> 
> 	mask = dwmci_readl(host, DWMCI_RINTSTS);
> 
> 	// Hardware asserts DWMCI_INTMSK_DTO here
> 
> 	dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_DTO);
> 
> 	if (mask & DWMCI_INTMSK_DTO) {
> 		// Unreachable as DTO is cleared without being handled!
> 		return 0;
> 	}
> 
> Only clear interrupts that we have seen and are handling so that DTO is
> not missed.
> 
> Signed-off-by: John Keeping <john at metanate.com>
> ---
>  drivers/mmc/dw_mmc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
> index 4232c5eb8c..5085a3b491 100644
> --- a/drivers/mmc/dw_mmc.c
> +++ b/drivers/mmc/dw_mmc.c
> @@ -168,7 +168,8 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
>  			if (data->flags == MMC_DATA_READ &&
>  			    (mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO))) {
>  				dwmci_writel(host, DWMCI_RINTSTS,
> -					     DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO);
> +					     mask & (DWMCI_INTMSK_RXDR |
> +						     DWMCI_INTMSK_DTO));
>  				while (size) {
>  					ret = dwmci_fifo_ready(host,
>  							DWMCI_FIFO_EMPTY,

Tested-by: Jerome Forissier <jerome.forissier at linaro.org> (Rock PI 4B)

Boot logs:

- 2022.04 without this patch:

[...]
U-Boot SPL 2022.04 (Apr 04 2022 - 14:31:32 +0000)

Trying to boot from MMC1

## Checking hash(es) for config config_1 ... sha1,rsa2048:dev+ OK

## Checking hash(es) for Image atf_1 ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image uboot ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image fdt_1 ... sha1+ sha1,rsa2048:dev+ OK

spl_load_simple_fit: can't load image loadables index 1 (ret = -5)

mmc_load_image_raw_sector: mmc block read error


[...]

- 2022.04 with this patch:

[...]
U-Boot SPL 2022.04 (Apr 04 2022 - 14:31:32 +0000)

Trying to boot from MMC1

## Checking hash(es) for config config_1 ... sha1,rsa2048:dev+ OK

## Checking hash(es) for Image atf_1 ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image uboot ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image fdt_1 ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image atf_2 ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image atf_3 ... sha1+ sha1,rsa2048:dev+ OK

## Checking hash(es) for Image atf_4 ... sha1+ sha1,rsa2048:dev+ OK

NOTICE:  BL31: v2.6(debug):v2.6-879-gc3bdd3d3cf-dirty

[...]

Thanks,
-- 
Jerome