Subject: [PATCH] ARM: OMAP: Fix kernel panic in dmtimer probe

From: [email-masked] (Jon Hunter)
Date: Thu, 8 Nov 2012 19:13:59 -0600

On 11/08/2012 06:17 PM, Jon Hunter wrote:
> When booting with device-tree the kernel is panicing in the probe of the
> DMTIMER driver. The panic is caused because the pointer to platform_data
> structure is NULL when booting with device-tree and the driver is
> attempting to access the structure without checking if the pointer is
> valid.
> 
> Fix this by moving the code that accesses the platform data structure
> under the "else" clause of the "if (dev->of_node)" statement because
> here the pointer to platform_data is guaranteed to be valid. The code
> accessing the "timer_capability" member of the platform data is simply
> removed as this is already handled under the else clause.
> 
> This regression was introduced while integrating commit "ARM: OMAP: Add
> DT support for timer driver" to add device-tree support to the DMTIMER
> driver and commit "ARM: OMAP: Move omap-pm-noop.c local to mach-omap2"
> to prepare for single zImage support.

By the way, I meant to add ...

Reported-by: Tony Lindgren <[email-masked]>

Jon

> Signed-off-by: Jon Hunter <[email-masked]>
> ---
>  arch/arm/plat-omap/dmtimer.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
> index 38c12ef..9dca23e 100644
> --- a/arch/arm/plat-omap/dmtimer.c
> +++ b/arch/arm/plat-omap/dmtimer.c
> @@ -799,12 +799,11 @@ static int __devinit omap_dm_timer_probe(struct platform_device *pdev)
>  		timer->id = pdev->id;
>  		timer->capability = pdata->timer_capability;
>  		timer->reserved = omap_dm_timer_reserved_systimer(timer->id);
> +		timer->get_context_loss_count = pdata->get_context_loss_count;
>  	}
>  
>  	timer->irq = irq->start;
>  	timer->pdev = pdev;
> -	timer->capability = pdata->timer_capability;
> -	timer->get_context_loss_count = pdata->get_context_loss_count;
>  
>  	/* Skip pm_runtime_enable for OMAP1 */
>  	if (!(timer->capability & OMAP_TIMER_NEEDS_RESET)) {
>