Linux-RTC Archive on lore.kernel.org
 help / color / Atom feed
From: Michal Simek <michal.simek@xilinx.com>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Michal Simek <monstr@monstr.eu>
Cc: Srinivas Neeli <srinivas.neeli@xilinx.com>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Srinivas Goud <sgoud@xilinx.com>,
	Shubhrajyoti Datta <shubhraj@xilinx.com>,
	linux-rtc@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	linux-arm <linux-arm-kernel@lists.infradead.org>,
	git <git@xilinx.com>
Subject: Re: [PATCH] rtc: zynqmp: Clear alarm interrupt status before interrupt enable
Date: Tue, 11 Feb 2020 11:40:40 +0100
Message-ID: <49ee656d-0d5e-c97f-f77e-04b1f1a187b4@xilinx.com> (raw)
In-Reply-To: <20200211103939.GD3527@piout.net>

On 11. 02. 20 11:39, Alexandre Belloni wrote:
> On 10/02/2020 12:48:14+0100, Michal Simek wrote:
>> Hi,
>>
>> čt 12. 12. 2019 v 14:01 odesílatel Srinivas Neeli
>> <srinivas.neeli@xilinx.com> napsal:
>>>
>>> Fix multiple occurring interrupts for alarm interrupt. RTC module doesn't
>>> clear the alarm interrupt status bit immediately after the interrupt is
>>> triggered.This is due to the sticky nature of the alarm interrupt status
>>> register. The alarm interrupt status register can be cleared only after
>>> the second counter outruns the set alarm value. To fix multiple spurious
>>> interrupts, disable alarm interrupt in the handler and clear the status
>>> bit before enabling the alarm interrupt.
>>>
>>> Fixes: 11143c19eb57 ("rtc: add xilinx zynqmp rtc driver")
>>> Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
>>> ---
>>>  drivers/rtc/rtc-zynqmp.c | 29 ++++++++++++++++++++++++-----
>>>  1 file changed, 24 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c
>>> index 5786866c09e9..d311e3ef1f21 100644
>>> --- a/drivers/rtc/rtc-zynqmp.c
>>> +++ b/drivers/rtc/rtc-zynqmp.c
>>> @@ -38,6 +38,8 @@
>>>
>>>  #define RTC_CALIB_DEF          0x198233
>>>  #define RTC_CALIB_MASK         0x1FFFFF
>>> +#define RTC_ALRM_MASK          BIT(1)
>>> +#define RTC_MSEC               1000
>>>
>>>  struct xlnx_rtc_dev {
>>>         struct rtc_device       *rtc;
>>> @@ -124,11 +126,28 @@ static int xlnx_rtc_alarm_irq_enable(struct device *dev, u32 enabled)
>>>  {
>>>         struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
>>>
>>
>> here shouldn't be empty line.
>>
>>> -       if (enabled)
>>> +       unsigned int status;
>>> +       ulong timeout;
>>> +
>>> +       timeout = jiffies + msecs_to_jiffies(RTC_MSEC);
>>> +
>>> +       if (enabled) {
>>> +               while (1) {
>>> +                       status = readl(xrtcdev->reg_base + RTC_INT_STS);
>>> +                       if (!((status & RTC_ALRM_MASK) == RTC_ALRM_MASK))
>>> +                               break;
>>> +
>>> +                       if (time_after_eq(jiffies, timeout)) {
>>> +                               dev_err(dev, "Time out occur, while clearing alarm status bit\n");
>>> +                               return -ETIMEDOUT;
>>> +                       }
>>> +                       writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_STS);
>>> +               }
>>> +
>>>                 writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_EN);
>>> -       else
>>> +       } else {
>>>                 writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
>>> -
>>> +       }
>>
>> And here it was good to have empty line.
>>
>>>         return 0;
>>>  }
>>>
>>> @@ -183,8 +202,8 @@ static irqreturn_t xlnx_rtc_interrupt(int irq, void *id)
>>>         if (!(status & (RTC_INT_SEC | RTC_INT_ALRM)))
>>>                 return IRQ_NONE;
>>>
>>> -       /* Clear RTC_INT_ALRM interrupt only */
>>> -       writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_STS);
>>> +       /* Disable RTC_INT_ALRM interrupt only */
>>> +       writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
>>>
>>>         if (status & RTC_INT_ALRM)
>>>                 rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_AF);
>>> --
>>> 2.7.4
>>
>> Other then these two above things look good.
>>
>> Alexandre: Any issue with this patch?
>>
> 
> No issue, I was kind of waiting for your review. I'll take the patch
> once your comments are addressed.

Ok. Thanks,
Michal



      reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-12 13:00 Srinivas Neeli
2020-02-10 11:48 ` Michal Simek
2020-02-11 10:39   ` Alexandre Belloni
2020-02-11 10:40     ` Michal Simek [this message]

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49ee656d-0d5e-c97f-f77e-04b1f1a187b4@xilinx.com \
    --to=michal.simek@xilinx.com \
    --cc=a.zummo@towertech.it \
    --cc=alexandre.belloni@bootlin.com \
    --cc=git@xilinx.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rtc@vger.kernel.org \
    --cc=monstr@monstr.eu \
    --cc=sgoud@xilinx.com \
    --cc=shubhraj@xilinx.com \
    --cc=srinivas.neeli@xilinx.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-RTC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-rtc/0 linux-rtc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-rtc linux-rtc/ https://lore.kernel.org/linux-rtc \
		linux-rtc@vger.kernel.org
	public-inbox-index linux-rtc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-rtc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git