Re: [PATCH 1/2 v2] mtd: maps: Leave assigned complex mappings

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

Hi Linus,

On Mon, 12 Nov 2018 22:07:28 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

> The simple_map_init() may need to be called with some
> function pointers already assigned for complex mappings,
> just bail out if complex handlers have already been
> assigned.
> 
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Rebase on latest MTD development branch
> - Use a new approach as the code changed under me
> ---
>  drivers/mtd/maps/map_funcs.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mtd/maps/map_funcs.c b/drivers/mtd/maps/map_funcs.c
> index 3f268370eeca..60e132293e1c 100644
> --- a/drivers/mtd/maps/map_funcs.c
> +++ b/drivers/mtd/maps/map_funcs.c
> @@ -31,6 +31,10 @@ static void __xipram simple_map_copy_to(struct map_info *map, unsigned long to,
>  
>  void simple_map_init(struct map_info *map)
>  {
> +	/* Complex map functions already assigned */
> +	if (map->read)
> +		return;
> +
>  	BUG_ON(!map_bankwidth_supported(map->bankwidth));
>  
>  	map->read = simple_map_read;

Can we move that to the physmap driver?

--->8---
diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c
index e8c3b250d842..043c7de39757 100644
--- a/drivers/mtd/maps/physmap-core.c
+++ b/drivers/mtd/maps/physmap-core.c
@@ -514,10 +514,16 @@ static int physmap_flash_probe(struct platform_device *dev)
                        err = physmap_addr_gpios_map_init(&info->maps[i]);
                        if (err)
                                goto err_out;
-               } else {
-                       simple_map_init(&info->maps[i]);
                }
 
+               /*
+                * Only use the simple_map implementation if map hooks are not
+                * implemented. Since map->read() is mandatory checking for its
+                * presence is enough.
+                */
+               if (map->read)
+                       simple_map_init(&info->maps[i]);
+
                if (info->probe_type) {
                        info->mtds[i] = do_map_probe(info->probe_type,
                                                     &info->maps[i]);