From: David Hauweele <david@hauweele.net>
To: Alan Ott <alan@signal11.us>
Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>,
Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
linux-zigbee-devel@lists.sourceforge.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [Linux-zigbee-devel] [PATCH 2/2] mrf24j40: Keep the interrupt line enabled
Date: Thu, 16 May 2013 23:34:11 +0200 [thread overview]
Message-ID: <CAO+c-UWi5UH-ZN5G0JiJCrCrScaYprKT7jLpFH0wEJecgoHgig@mail.gmail.com> (raw)
In-Reply-To: <5191B5C4.2020609@signal11.us>
I have seen the interrupt line going low forever with heavy traffic.
The at86rf230 driver has two isr, one for edge-triggered and another
for level-triggered interrupt. The latter uses
disable_irq_nosync/enable_irq which makes sense for level-triggered
interrupt. Otherwise the interrupt would be triggered again and again
until the scheduled work read the status register.
However I don't see the use of disable_irq/enable_irq with an
edge-triggered interrupt. Perhaps I'm missing something. Though I
don't see any harm using it anyway. As you said the interrupt should
be delayed until enable_irq() is called. In particular when
CONFIG_HARDIRQS_SW_RESEND is set.
David
2013/5/14 Alan Ott <alan@signal11.us>:
> On 5/9/13 11:19 AM, David Hauweele wrote:
>>
>> Disabling the interrupt line could miss an IRQ and leave the line into a
>> low state hence locking the driver.
>>
>
> Have you observed this? My understanding is that the interrupt won't be lost
> but instead delayed until enable_irq() is called.
>
> I got this pattern from the other 802.15.4 drivers. Perhaps my understanding
> is wrong.
>
>
>
>> Signed-off-by: David Hauweele <david@hauweele.net>
>> ---
>> drivers/net/ieee802154/mrf24j40.c | 7 +------
>> 1 file changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/drivers/net/ieee802154/mrf24j40.c
>> b/drivers/net/ieee802154/mrf24j40.c
>> index 1e3ddf3..6ef32f7 100644
>> --- a/drivers/net/ieee802154/mrf24j40.c
>> +++ b/drivers/net/ieee802154/mrf24j40.c
>> @@ -603,8 +603,6 @@ static irqreturn_t mrf24j40_isr(int irq, void *data)
>> {
>> struct mrf24j40 *devrec = data;
>>
>> - disable_irq_nosync(irq);
>> -
>> schedule_work(&devrec->irqwork);
>>
>> return IRQ_HANDLED;
>> @@ -619,7 +617,7 @@ static void mrf24j40_isrwork(struct work_struct *work)
>> /* Read the interrupt status */
>> ret = read_short_reg(devrec, REG_INTSTAT, &intstat);
>> if (ret)
>> - goto out;
>> + return;
>>
>> /* Check for TX complete */
>> if (intstat & 0x1)
>> @@ -628,9 +626,6 @@ static void mrf24j40_isrwork(struct work_struct *work)
>> /* Check for Rx */
>> if (intstat & 0x8)
>> schedule_work(&devrec->rxwork);
>> -
>> -out:
>> - enable_irq(devrec->spi->irq);
>> }
>>
>> static void mrf24j40_rxwork(struct work_struct *work)
>>
>
next prev parent reply other threads:[~2013-05-16 21:34 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-09 15:19 [PATCH 1/2] mrf24j40: Avoid transmission while receiving a frame David Hauweele
2013-05-09 15:19 ` [PATCH 2/2] mrf24j40: Keep the interrupt line enabled David Hauweele
[not found] ` <1368112788-25701-2-git-send-email-david-1EggE+PRa6vk1uMJSBkQmQ@public.gmane.org>
2013-05-14 3:55 ` Alan Ott
2013-05-16 21:34 ` David Hauweele [this message]
2013-05-19 23:04 ` [Linux-zigbee-devel] " Alan Ott
2013-05-21 16:17 ` David Hauweele
[not found] ` <CAO+c-UXymPjYysvh2kM36gcOsL3P51YWq+aYhEqX8oCySwBcaQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-21 18:22 ` Alan Ott
2013-05-14 3:22 ` [Linux-zigbee-devel] [PATCH 1/2] mrf24j40: Avoid transmission while receiving a frame Alan Ott
[not found] ` <5191ADE4.8040709-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
2013-05-16 17:45 ` David Hauweele
[not found] ` <CAO+c-UVJQJbmmmCS4hxAEYHKa8gEU1Bs=y+Rv_A75UHeBZxc+w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-20 0:05 ` [PATCH testing] mrf24j40: Move INIT_COMPLETION to before the packet is sent Alan Ott
2013-05-22 2:01 ` [PATCH beta 1] 0/3] Fix race conditions in mrf24j40 interrupts Alan Ott
[not found] ` <1369188080-8904-1-git-send-email-alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
2013-05-22 2:01 ` [PATCH beta 1] 1/3] mrf24j40: Move INIT_COMPLETION() to before packet transmission Alan Ott
2013-05-22 2:01 ` [PATCH beta 1] 2/3] mrf24j40: Use threaded IRQ handler Alan Ott
2013-10-06 3:52 ` [PATCH v1 0/3] Fix race conditions in mrf24j40 interrupts Alan Ott
[not found] ` <1381031544-2960-1-git-send-email-alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
2013-10-06 3:52 ` [PATCH v1 1/3] mrf24j40: Move INIT_COMPLETION() to before packet transmission Alan Ott
2013-10-06 3:52 ` [PATCH v1 2/3] mrf24j40: Use threaded IRQ handler Alan Ott
2013-10-06 3:52 ` [PATCH v1 3/3] mrf24j40: Use level-triggered interrupts Alan Ott
2013-10-08 19:32 ` [PATCH v1 0/3] Fix race conditions in mrf24j40 interrupts David Miller
2013-05-22 2:01 ` [PATCH beta 1] 3/3] mrf24j40: Use level-triggered interrupts Alan Ott
2013-05-22 2:03 ` [PATCH beta 1] 0/3] Fix race conditions in mrf24j40 interrupts Alan Ott
2013-05-22 20:32 ` David Hauweele
[not found] ` <CAO+c-UV1bZZEE=9=7VVn3f1eLWzCpYCK9eZnnvzNwcPOKKtKLA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-23 6:36 ` Alan Ott
[not found] ` <519DB8E6.4020709-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
2013-05-23 17:54 ` David Hauweele
2013-05-23 19:33 ` Alan Ott
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