Re: [PATCH v2 1/2] mtd: cfi: Support early CFI fixups

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

Hi Aaron,

On Mon, 30 Apr 2018 11:34:49 -0500 (CDT)
Aaron Sierra <asierra@xes-inc.com> wrote:

> Some CFI devices need fixups that affect the number of chips detected,
> but the current fixup infrastructure (struct cfi_fixup and cfi_fixup())
> does not cover this situation.
> 
> Introduce struct cfi_early_fixup and cfi_early_fixup() to fill the void.
> 
> Signed-off-by: Aaron Sierra <asierra@xes-inc.com>

This version looks good to me, just a few minor things which I can fix
when applying if you agree with the changes I suggest.

> ---
> 
>  v2 - Split into two patches. One adding infrastructure and one adding
>       the first early fixup.
>     - Define struct cfi_early_fixup and cfi_early_fixup() in cfi_probe.c
> 
>  drivers/mtd/chips/cfi_probe.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/mtd/chips/cfi_probe.c b/drivers/mtd/chips/cfi_probe.c
> index e8d0164..c05deac 100644
> --- a/drivers/mtd/chips/cfi_probe.c
> +++ b/drivers/mtd/chips/cfi_probe.c
> @@ -63,6 +63,29 @@ do { \
>  
>  #endif
>  
> +/*
> + * This fixup occurs immediately after reading the CFI structure and can affect
> + * the number of chips detected, unlike cfi_fixup, which occurs after an
> + * mtd_info structure has been created for the chip.
> + */
> +struct cfi_early_fixup {
> +	uint16_t mfr;
> +	uint16_t id;
> +	void (*fixup)(struct cfi_private *cfi);
> +};
> +
> +void cfi_early_fixup(struct cfi_private *cfi, struct cfi_early_fixup *fixups)
> +{
> +	struct cfi_early_fixup *f;

	const struct cfi_early_fixup *f;

> +
> +	for (f = fixups; f->fixup; f++) {
> +		if (((f->mfr == CFI_MFR_ANY) || (f->mfr == cfi->mfr)) &&
> +		    ((f->id == CFI_ID_ANY) || (f->id == cfi->id))) {
> +			f->fixup(cfi);
> +		}
> +	}
> +}
> +
>  /* check for QRY.
>     in: interleave,type,mode
>     ret: table index, <0 for error
> @@ -151,6 +174,10 @@ static int __xipram cfi_probe_chip(struct map_info *map, __u32 base,
>  	return 1;
>  }
>  
> +static struct cfi_early_fixup cfi_early_fixup_table[] = {

static const ...

> +	{ 0, 0, NULL },

No need to fill all the fields, just do

	{ },

and the compiler will initialize everything to zero.

> +};
> +
>  static int __xipram cfi_chip_setup(struct map_info *map,
>  				   struct cfi_private *cfi)
>  {
> @@ -235,6 +262,8 @@ static int __xipram cfi_chip_setup(struct map_info *map,
>  	cfi_qry_mode_off(base, map, cfi);
>  	xip_allowed(base, map);
>  
> +	cfi_early_fixup(cfi, cfi_early_fixup_table);
> +
>  	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank. Manufacturer ID %#08x Chip ID %#08x\n",
>  	       map->name, cfi->interleave, cfi->device_type*8, base,
>  	       map->bankwidth*8, cfi->mfr, cfi->id);

Thanks,

Boris