Re: [PATCH] staging: fsl-mc: fix warning in DT ranges parser

[Laurentiu Tudor]

Hi Arnd,

On 02/27/2017 10:42 PM, Arnd Bergmann wrote:
> The fsl-mc-bus driver in staging contains a copy of the standard
> 'ranges' property parsing algorithm with a hack to treat a missing
> property the same way as an empty one. This code produces false-positive
> warnings for me in an allmodconfig build:
>
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c: In function 'fsl_mc_bus_probe':
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c:645:6: error: 'mc_size_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c:682:8: error: 'mc_addr_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c:644:6: note: 'mc_addr_cells' was declared here
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c:684:8: error: 'paddr_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/staging/fsl-mc/bus/fsl-mc-bus.c:643:6: note: 'paddr_cells' was declared here
>
> To avoid the warnings, I'm simplifying the argument handling to pass
> the number of valid ranges in the property as the function return code
> rather than passing it by reference. With this change, gcc can see that
> we don't evaluate the cell numbers for an missing ranges property.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Looks good to me, i've tested it and did not see any issues, so here's an:

Acked-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

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Thanks & Best Regards, Laurentiu