[PATCH] mtd: physmap: Fix mtd device size

[PATCH] mtd: physmap: Fix mtd device size

[Victor Fusco]

This patch fixes the mtd device size calculation when there is no gpio
defined. The previous size calculation could return values lower than
those defined on the 'reg' field of the Device Tree, rasing 'attempt to
access beyond end of device' errors during device access.

Signed-off-by: Victor Fusco <victor@cartesi.io>
---
 drivers/mtd/maps/physmap-core.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c
index 8f7f966fa9a7..27cc6ac01ea8 100644
--- a/drivers/mtd/maps/physmap-core.c
+++ b/drivers/mtd/maps/physmap-core.c
@@ -520,17 +520,19 @@ static int physmap_flash_probe(struct platform_device *dev)
 		if (!info->maps[i].phys)
 			info->maps[i].phys = res->start;
 
-		info->win_order = get_bitmask_order(resource_size(res)) - 1;
-		info->maps[i].size = BIT(info->win_order +
-					 (info->gpios ?
-					  info->gpios->ndescs : 0));
-
 		info->maps[i].map_priv_1 = (unsigned long)dev;
 
 		if (info->gpios) {
+			info->win_order = get_bitmask_order(resource_size(res)) - 1;
+			info->maps[i].size = BIT(info->win_order +
+					         info->gpios->ndescs);
+
 			err = physmap_addr_gpios_map_init(&info->maps[i]);
 			if (err)
 				goto err_out;
+		} else {
+			info->maps[i].size = resource_size(res);
+
 		}
 
 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS

base-commit: 5076190daded2197f62fe92cf69674488be44175
-- 
2.17.1


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Re: [PATCH] mtd: physmap: Fix mtd device size

[Miquel Raynal]

Hi Victor,

Victor Fusco <victor@cartesi.io> wrote on Thu, 19 Mar 2020 14:41:29
+0000:

> This patch fixes the mtd device size calculation when there is no gpio

s/mtd/MTD/

S/gpio/GPIO/

> defined. The previous size calculation could return values lower than
> those defined on the 'reg' field of the Device Tree, rasing 'attempt to

s/rasing/raising/ ?

> access beyond end of device' errors during device access.
> 
> Signed-off-by: Victor Fusco <victor@cartesi.io>
> ---
>  drivers/mtd/maps/physmap-core.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c
> index 8f7f966fa9a7..27cc6ac01ea8 100644
> --- a/drivers/mtd/maps/physmap-core.c
> +++ b/drivers/mtd/maps/physmap-core.c
> @@ -520,17 +520,19 @@ static int physmap_flash_probe(struct platform_device *dev)
>  		if (!info->maps[i].phys)
>  			info->maps[i].phys = res->start;
>  
> -		info->win_order = get_bitmask_order(resource_size(res)) - 1;
> -		info->maps[i].size = BIT(info->win_order +
> -					 (info->gpios ?
> -					  info->gpios->ndescs : 0));
> -
>  		info->maps[i].map_priv_1 = (unsigned long)dev;
>  
>  		if (info->gpios) {
> +			info->win_order = get_bitmask_order(resource_size(res)) - 1;
> +			info->maps[i].size = BIT(info->win_order +
> +					         info->gpios->ndescs);
> +
>  			err = physmap_addr_gpios_map_init(&info->maps[i]);
>  			if (err)
>  				goto err_out;
> +		} else {
> +			info->maps[i].size = resource_size(res);

I didn't check the driver but are you sure info->win_order and
maps[i].map_priv_1 do not need to be initialized? Also are these fields
still needed if you stop using them? (just asking)

> +

Extra new line

>  		}
>  
>  #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
> 
> base-commit: 5076190daded2197f62fe92cf69674488be44175

Thanks,
Miquèl

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