Re: [PATCH] watchdog: qcom: fix kernel panic due to external abort on non-linefetch

[Guenter Roeck]

On 11/13/2016 05:11 PM, Christian Lamparter wrote:
> This patch fixes a off-by-one in the "watchdog: qcom: add option for
> standalone watchdog not in timer block" patch that causes the
> following panic on boot:
>
> > Unhandled fault: external abort on non-linefetch (0x1008) at 0xc8874002
> > pgd = c0204000
> > [c8874002] *pgd=87806811, *pte=0b017653, *ppte=0b017453
> > Internal error: : 1008 [#1] SMP ARM
> > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.8.6 #0
> > Hardware name: Generic DT based system
> > PC is at 0xc02222f4
> > LR is at 0x1
> > pc : [<c02222f4>]    lr : [<00000001>]    psr: 00000113
> > sp : c782fc98  ip : 00000003  fp : 00000000
> > r10: 00000004  r9 : c782e000  r8 : c04ab98c
> > r7 : 00000001  r6 : c8874002  r5 : c782fe00  r4 : 00000002
> > r3 : 00000000  r2 : c782fe00  r1 : 00100000  r0 : c8874002
> > Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
> > Control: 10c5387d  Table: 8020406a  DAC: 00000051
> > Process swapper/0 (pid: 1, stack limit = 0xc782e210)
> > Stack: (0xc782fc98 to 0xc7830000)
> > [...]
>
> The WDT_STS (status) needs to be translated via wdt_addr as well.
>
> fixes: f0d9d0f4b44a ("watchdog: qcom: add option for standalone watchdog not in timer block")
> Cc: stable@xxxxxxxxxxxxxxx # 4.8
> Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>  drivers/watchdog/qcom-wdt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
> index 5796b5d..4f47b5e 100644
> --- a/drivers/watchdog/qcom-wdt.c
> +++ b/drivers/watchdog/qcom-wdt.c
> @@ -209,7 +209,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
>  	wdt->wdd.parent = &pdev->dev;
>  	wdt->layout = regs;
>
> -	if (readl(wdt->base + WDT_STS) & 1)
> +	if (readl(wdt_addr(wdt, WDT_STS)) & 1)
>  		wdt->wdd.bootstatus = WDIOF_CARDRESET;
>
>  	/*