Hi,
On Fri, Oct 31, 2014 at 10:20:06AM -0500, Dinh Nguyen wrote:
> >> @@ -339,7 +339,8 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
> >> }
> >> /* Change to L0 state */
> >> hsotg->lx_state = DWC2_L0;
> >> - call_gadget(hsotg, resume);
> >> + if (!IS_ERR(hsotg->clk))
> >> + call_gadget(hsotg, resume);
> >
> > instead of exposing the clock detail to the entire driver, add IS_ERR()
> > checks to resume and suspend instead. In fact, NULL is a valid clock, so
> > you might as well:
> >
> > clk = clk_get(foo, bar);
> > if (IS_ERR(clk))
> > dwc->clk = NULL;
> > else
> > dwc->clk = clk;
> >
> > Then you don't need any IS_ERR() checks sprinkled around the driver.
>
> But we would still need to check for the clock before accessing gadget
> functionality right?
>
> if (dwc2->clk)
> call_gadget();
Read my comment again. "NULL is a valid clock". Look at what
clk_enable() does when a NULL pointer is passed:
static int __clk_enable(struct clk *clk)
{
int ret = 0;
if (!clk)
return 0;
if (WARN_ON(clk->prepare_count == 0))
return -ESHUTDOWN;
if (clk->enable_count == 0) {
ret = __clk_enable(clk->parent);
if (ret)
return ret;
if (clk->ops->enable) {
ret = clk->ops->enable(clk->hw);
if (ret) {
__clk_disable(clk->parent);
return ret;
}
}
}
clk->enable_count++;
return 0;
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
int ret;
flags = clk_enable_lock();
ret = __clk_enable(clk);
clk_enable_unlock(flags);
return ret;
}
EXPORT_SYMBOL_GPL(clk_enable);
> >> @@ -400,7 +401,8 @@ static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
> >> "DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
> >> !!(dsts & DSTS_SUSPSTS),
> >> hsotg->hw_params.power_optimized);
> >> - call_gadget(hsotg, suspend);
> >> + if (!IS_ERR(hsotg->clk))
> >> + call_gadget(hsotg, suspend);
> >> } else {
> >> if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
> >> dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
> >> @@ -477,7 +479,8 @@ irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
> >> spin_lock(&hsotg->lock);
> >>
> >> if (dwc2_is_device_mode(hsotg))
> >> - retval = s3c_hsotg_irq(irq, dev);
> >> + if (!IS_ERR(hsotg->clk))
> >> + retval = s3c_hsotg_irq(irq, dev);
> >
> > wait a minute, if there is no clock we don't call the gadget interrupt
> > handler ? Why ? Who will disable the IRQ line ?
>
> This portion is no static int __clk_enable(struct clk *clk)
huh ? What I mean is that this has the potential of leaving that IRQ
line enabled. Imagine you don't have a clock and s3c_hsotg_irq() isn't
called, then a peripheral IRQ fires, since the handler isn't called, who
will clear the interrupt ?
--
balbi
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