Re: [PATCH] PCI/ASPM: Change type of threshold_ns variable to u32

From: Andy Shevchenko
Date: Wed Feb 28 2018 - 04:40:54 EST


On Wed, Feb 28, 2018 at 1:19 AM, Gustavo A. R. Silva
<garsilva@xxxxxxxxxxxxxx> wrote:
> It seems that the expression threshold_us * 1000 will never exceed the
> 32-bit limits [1]. So changing the type of threshold_ns from u64 to u32
> seems sensible [2].
>
> [1] https://marc.info/?l=linux-kernel&m=151855021100725&w=2
> [2] https://marc.info/?l=linux-kernel&m=151976318924615&w=2
>

Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> Addresses-Coverity-ID: 1462501
> Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
> ---
> drivers/pci/pcie/aspm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index 57feef2..8633fc4 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -322,7 +322,7 @@ static u32 calc_l1ss_pwron(struct pci_dev *pdev, u32 scale, u32 val)
>
> static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value)
> {
> - u64 threshold_ns = threshold_us * 1000;
> + u32 threshold_ns = threshold_us * 1000;
>
> /* See PCIe r3.1, sec 7.33.3 and sec 6.18 */
> if (threshold_ns < 32) {
> --
> 2.7.4
>



--
With Best Regards,
Andy Shevchenko