Hi Viresh,
On 05/23/2014 08:55 PM, Viresh Kumar wrote:
Clockevents core now supports ->set_dev_mode() (as a replacement to ->set_mode()), with capability to return error codes.
Migrate all ARM specific clockevent drivers to implement this new callback.
Drivers now return -ENOSYS when a unsupported mode is passed to their ->set_dev_mode() callbacks and return 0 on success.
Most of the changes are automated with help of Coccinelle (http://coccinelle.lip6.fr/) and the ones left are around the switch block which are handled manually.
Some drivers had a WARN()/BUG()/pr_err()/empty-implementation for unsupported modes. These statements and unsupported modes are removed now as proper error handling with a WARN_ON() is done at clockevents core.
A simplified version of the semantic patch is: diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c index fd6bff0..9ed3845 100644 --- a/arch/arm/common/timer-sp.c +++ b/arch/arm/common/timer-sp.c @@ -127,7 +127,7 @@ static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id) return IRQ_HANDLED; }
-static void sp804_set_mode(enum clock_event_mode mode, +static int sp804_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE; @@ -147,11 +147,14 @@ static void sp804_set_mode(enum clock_event_mode mode,
case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN:
- default:
case CLOCK_EVT_MODE_RESUME: break;
default:
return -ENOSYS;}
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
How about cases like above where just before entering the switch block, where some code(in this case writel) is executed, but for default cases they return early and do not execute the code(writel() in this case) after the switch block. Is that ok?
[snip]
void __iomem *at91_st_base; diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c index 0a9e2fc..9698eb6 100644 --- a/arch/arm/mach-at91/at91sam926x_time.c +++ b/arch/arm/mach-at91/at91sam926x_time.c @@ -83,7 +83,7 @@ static struct clocksource pit_clk = { /*
- Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/ -static void +static int pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev) { switch (mode) { @@ -93,9 +93,6 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev) pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN | AT91_PIT_PITIEN); break;
- case CLOCK_EVT_MODE_ONESHOT:
BUG();/* FALLTHROUGH */
Don't you think you should keep the BUG_ON() as is? This becomes a WARN_ON() instead. Would that be ok? While the original code thinks it unwise to continue executing after this, this patch allows that to happen.
Regards Preeti U Murthy