[U-Boot] [PATCH 1/4] mmc: dw_mmc: check fifo status with a timeout in fifo mode

[Philipp Tomsich]

> On 21.09.2018, at 10:59, Heiko Stuebner <heiko at sntech.de> wrote:
> 
> While trying to enable the dw_mmc on rk3188 I managed to confuse
> and hang the dw_mmc controller into not delivering further data.
> The fifo state never became ready and the driver was iterating in
> the while loop reading 0-byte packets forever.
> 
> So inspired by how other implementations handle this, check the fifo-
> state beforhand and add a timeout to catch any glaring fifo issues
> without hanging uboot altogether.
> 
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>