[PATCH] mmc: dwmmc: only clear handled interrupts

[Quentin Schulz]

Hi John,

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>

Awesome! I was having what I thought were stability issues on a board 
I'm bringing up and this fixes the issue. Thanks!

Tested-by: Quentin Schulz <quentin.schulz at theobroma-systems.com> 
(PX30-based eMMC+SD, Puma RK3399 eMMC)

Cheers,
Quentin