On Tue, Mar 21, 2017 at 11:03 AM, Thomas Petazzoni
<thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote:
> In commit eea628199d5b ("mtd: Add device-tree support to fsmc_nand"),
> Device Tree support was added to the fmsc_nand driver. However, this
> code has a bug in how it handles the bank-width DT property to set the
> bus width.
>
> Indeed, in the function fsmc_nand_probe_config_dt() that parses the
> Device Tree, it sets pdata->width to either 8 or 16 depending on the
> value of the bank-width DT property.
>
> Then, the ->probe() function will test if pdata->width is equal to
> FSMC_NAND_BW16 (which is 2) to set NAND_BUSWIDTH_16 in
> nand->options. Therefore, with the DT probing, this condition will never
> match.
>
> This commit fixes that by removing the "width" field from
> fsmc_nand_platform_data and instead have the fsmc_nand_probe_config_dt()
> function directly set the appropriate nand->options value.
>
> It is worth mentioning that if this commit gets backported to older
> kernels, prior to the drop of non-DT probing, then non-DT probing will
> be broken because nand->options will no longer be set to
> NAND_BUSWIDTH_16.
>
> Fixes: eea628199d5b ("mtd: Add device-tree support to fsmc_nand")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Good catch.
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Yours,
Linus Walleij