[U-Boot] [PATCH] mtd: uboot: Fix hanging during mtd list command

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Mon,  8 Oct 2018 13:23:06 -0500
Adam Ford <aford173@gmail.com> wrote:

> Some boards using simple NAND drivers (like omap3_logic) hang
> when executing the new 'mtd list' command.  This patch enhances
> the checks for conditions that would preclude mtd_probe_devices()
> from operating.
> 
> Fixes: 5db66b3aee6f ("cmd: mtd: add 'mtd' command")
> 
> Signed-off-by: Adam Ford <aford173@gmail.com>
> 
> diff --git a/drivers/mtd/mtd_uboot.c b/drivers/mtd/mtd_uboot.c
> index 6a211d52ff..91a4a8a9c0 100644
> --- a/drivers/mtd/mtd_uboot.c
> +++ b/drivers/mtd/mtd_uboot.c
> @@ -104,7 +104,14 @@ int mtd_probe_devices(void)
>  	mtd_probe_uclass_mtd_devs();
>  
>  	/* Check if mtdparts/mtdids changed since last call, otherwise: exit */
> -	if (!strcmp(mtdparts, old_mtdparts) && !strcmp(mtdids, old_mtdids))
> +	if ((!mtdparts && !old_mtdparts && !mtdids && !old_mtdids) ||
> +	    (mtdparts && old_mtdparts && mtdids && old_mtdids &&
> +	     !strcmp(mtdparts, old_mtdparts) &&
> +	     !strcmp(mtdids, old_mtdids)))
> +		return 0;
> +
> +	/* If either mtdparts or mtdids is empty, then exit */
> +	if (!mtdparts || !mtdids)
>  		return 0;

We should first remove all partitions before bailing out, hence my
proposal to place this check after the 'while (remaining_partitions)'
loop.

>  
>  	/* Update the local copy of mtdparts */