[PATCH] mci: sdhci: don't hang indefinitely waiting for DMA completion

[Marco Felsch]

On 23-08-24, Ahmad Fatoum wrote:
> barebox was observed to hang on an i.MX8MP while reading ext_csd from
> a broken eMMC that even bootROM refused to boot from. For PIO, we
> already have a maximum wait time of 10s. Do the same for DMA.
> 
> It's unlikely that in that state any further communication with the card
> will work, but at least, the system isn't stuck and the shell can be
> reached. The reset is done on the off-chance that the DMA would've completed
> after the 10s and corrupted memory if not disabled.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

Reviewed-by: Marco Felsch <m.felsch at pengutronix.de>