[PATCH] hpet: Drop unused variable 'm' in hpet_interrupt()

[PATCH] hpet: Drop unused variable 'm' in hpet_interrupt()

[Kefeng Wang]

../drivers/char/hpet.c:159:17: warning: variable ‘m’ set but not used
[-Wunused-but-set-variable]
   unsigned long m, t, mc, base, k;
                 ^
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 drivers/char/hpet.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 9ac6671bb514..039398cb14aa 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -156,12 +156,11 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
 	 * This has the effect of treating non-periodic like periodic.
 	 */
 	if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
-		unsigned long m, t, mc, base, k;
+		unsigned long t, mc, base, k;
 		struct hpet __iomem *hpet = devp->hd_hpet;
 		struct hpets *hpetp = devp->hd_hpets;
 
 		t = devp->hd_ireqfreq;
-		m = read_counter(&devp->hd_timer->hpet_compare);
 		mc = read_counter(&hpet->hpet_mc);
 		/* The time for the next interrupt would logically be t + m,
 		 * however, if we are very unlucky and the interrupt is delayed
-- 
2.20.1

Re: [PATCH] hpet: Drop unused variable 'm' in hpet_interrupt()

[Greg Kroah-Hartman]

On Thu, Jul 11, 2019 at 09:32:38PM +0800, Kefeng Wang wrote:
> ../drivers/char/hpet.c:159:17: warning: variable ‘m’ set but not used
> [-Wunused-but-set-variable]
>    unsigned long m, t, mc, base, k;
>                  ^
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>  drivers/char/hpet.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
> index 9ac6671bb514..039398cb14aa 100644
> --- a/drivers/char/hpet.c
> +++ b/drivers/char/hpet.c
> @@ -156,12 +156,11 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
>  	 * This has the effect of treating non-periodic like periodic.
>  	 */
>  	if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
> -		unsigned long m, t, mc, base, k;
> +		unsigned long t, mc, base, k;
>  		struct hpet __iomem *hpet = devp->hd_hpet;
>  		struct hpets *hpetp = devp->hd_hpets;
>  
>  		t = devp->hd_ireqfreq;
> -		m = read_counter(&devp->hd_timer->hpet_compare);

Are you sure this is ok to remove?  You are reading from the hardware
here, and often times that is required in order to achive something
else.

So this function does not "do nothing", be careful and you will have to
test this before I can take it.

thanks,

greg k-h