Re: [PATCH -next] gpio: generic: Revert to old error handling in bgpio_map

[Linus Walleij]

On Wed, Oct 21, 2015 at 9:12 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:

> Returning an error instead of NULL in bgpio_map if
> platform_get_resource_byname does not find a resource was introduced with
> commit cf3f2a2c8bae ("gpio: generic: improve error handling in bgpio_map").
> This results in several qemu runtime failures with default and non-default
> configurations, if attempts are made to boot from mmcblk0. Examples for
> failures with multi_v7_defconfig are
>
> Machine: vexpress-a9    dtb: vexpress-v2p-ca9
> Machine: vexpress-a15   dtb: vexpress-v2p-ca15-tc1
>
> Crash:
>
> VFS: Cannot open root device "mmcblk0" or unknown-block(0,0): error -6
> Please append a correct "root=" boot option; here are the available partitions:
> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
>
> Looking into the code, always returning an error if bgpio_map fails
> does not appear to make much sense, since the code in bgpio_setup_io
> specifically supports some of the resources to be NULL.
>
> Fixes: cf3f2a2c8bae ("gpio: generic: improve error handling in bgpio_map")
> Cc: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Patch/revert applied. Thanks for digging in and fixing this GÃnther!

Yours,
Linus Walleij
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