[PATCH v2] reset: brcmstb: Fix resource checks

[PATCH v2] reset: brcmstb: Fix resource checks

[Florian Fainelli]

The use of IS_ALIGNED() is incorrect, the typical resource we pass looks
like this: start: 0x8404318, size: 0x30. When using IS_ALIGNED() we will
get the following 0x8404318 & (0x18 - 1) = 0x10 which is definitively
not equal to 0, same goes with the size.

Replace this with an appropriate check on the start address and the
resource size to be a multiple of SW_INIT_BANK_SIZE.

Fixes: 77750bc089e4 ("reset: Add Broadcom STB SW_INIT reset controller driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v2:

- simply check that the resource size is at least SW_INIT_BANK_SIZE

 drivers/reset/reset-brcmstb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/reset/reset-brcmstb.c b/drivers/reset/reset-brcmstb.c
index a608f445dad6..208a87aaee53 100644
--- a/drivers/reset/reset-brcmstb.c
+++ b/drivers/reset/reset-brcmstb.c
@@ -91,8 +91,8 @@ static int brcmstb_reset_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!IS_ALIGNED(res->start, SW_INIT_BANK_SIZE) ||
-	    !IS_ALIGNED(resource_size(res), SW_INIT_BANK_SIZE)) {
+	if ((res->start & SW_INIT_BANK_SIZE) != SW_INIT_BANK_SIZE ||
+	    !DIV_ROUND_DOWN_ULL(resource_size(res), SW_INIT_BANK_SIZE)) {
 		dev_err(kdev, "incorrect register range\n");
 		return -EINVAL;
 	}
-- 
2.17.1

Re: [PATCH v2] reset: brcmstb: Fix resource checks

[Florian Fainelli]

On 10/31/19 9:18 PM, Florian Fainelli wrote:
> The use of IS_ALIGNED() is incorrect, the typical resource we pass looks
> like this: start: 0x8404318, size: 0x30. When using IS_ALIGNED() we will
> get the following 0x8404318 & (0x18 - 1) = 0x10 which is definitively
> not equal to 0, same goes with the size.
> 
> Replace this with an appropriate check on the start address and the
> resource size to be a multiple of SW_INIT_BANK_SIZE.
> 
> Fixes: 77750bc089e4 ("reset: Add Broadcom STB SW_INIT reset controller driver")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Philipp, I am just going to remove those register checks, this is overly
cautious for no particular reason, and we actually have platforms where
those registers checks would just flat out fail. Expect a v3 shortly,
thanks!
-- 
Florian