Re: [PATCH 03/12] rtc: omap: fix class-device registration

Felipe Balbi
2014-10-10T18:00:40Z

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On Thu, Oct 09, 2014 at 09:06:25PM +0200, Johan Hovold wrote:
> Make sure not to register the class device until after it has been
> configured and interrupt handlers registered at probe.
>
> Currently, the device is not fully configured (e.g. 24-hour mode) when
> the class device is registered, something which involves driver
> callbacks for example to read the current time.
>
> This reordering also prevents user space from enabling an alarm before
> an interrupt handler has been registered.
>
> Note that the interrupts are now registered using the platform-device
> rather than class-device name.
>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/rtc/rtc-omap.c | 32 +++++++++++++++++---------------
> 1 file changed, 17 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index 828cb9983cc2..2eca141e784e 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -147,8 +147,9 @@ static void rtc_wait_not_busy(void)
> /* now we have ~15 usec to read/write various registers */
> }
>
> -static irqreturn_t rtc_irq(int irq, void *rtc)
> +static irqreturn_t rtc_irq(int irq, void *dev_id)
> {
> + struct rtc_device *rtc = platform_get_drvdata(dev_id);
> unsigned long events = 0;
> u8 irq_data;
>
> @@ -164,7 +165,8 @@ static irqreturn_t rtc_irq(int irq, void *rtc)
> if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
> events |= RTC_IRQF | RTC_UF;
>
> - rtc_update_irq(rtc, 1, events);
> + if (rtc)
> + rtc_update_irq(rtc, 1, events);
>
> return IRQ_HANDLED;
> }
> @@ -416,17 +418,6 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
> rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
> }
>
> - device_init_wakeup(&pdev->dev, true);
> -
> - rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
> - &omap_rtc_ops, THIS_MODULE);
> - if (IS_ERR(rtc)) {
> - pr_debug("%s: can't register RTC device, err %ld\n",
> - pdev->name, PTR_ERR(rtc));
> - goto fail0;
> - }
> - platform_set_drvdata(pdev, rtc);
> -
> /* clear pending irqs, and set 1/second periodic,
> * which we'll use instead of update irqs
> */
> @@ -450,14 +441,14 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
>
> /* handle periodic and alarm irqs */
> if (devm_request_irq(&pdev->dev, omap_rtc_timer, rtc_irq, 0,
> - dev_name(&rtc->dev), rtc)) {
> + dev_name(&pdev->dev), pdev)) {
> pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
> pdev->name, omap_rtc_timer);
> goto fail0;
> }
> if ((omap_rtc_timer != omap_rtc_alarm) &&
> (devm_request_irq(&pdev->dev, omap_rtc_alarm, rtc_irq, 0,
> - dev_name(&rtc->dev), rtc))) {
> + dev_name(&pdev->dev), pdev))) {

i don't get it. Why pass pdev as cookie when all you need is rtc ?
Doesn't sound very good to me. Also, IRQ handler *must* be registered
only after RTC is registered. That's because if you request an IRQ here,
you could already have a pending interrupt and since you won't have a
valid rtc pointer you won't be able to clear the interrupt line.

--
balbi

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