From: Marc Kleine-Budde <mkl@pengutronix.de>
To: AnilKumar Ch <anilkumar@ti.com>
Cc: wg@grandegger.com, linux-can@vger.kernel.org, anantgole@ti.com,
nsekhar@ti.com
Subject: Re: [PATCH v2 1/4] can: c_can: fix an interrupt thrash issue with c_can driver
Date: Thu, 10 May 2012 21:13:46 +0200 [thread overview]
Message-ID: <4FAC136A.6040705@pengutronix.de> (raw)
In-Reply-To: <1336649657-4152-2-git-send-email-anilkumar@ti.com>
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05/10/2012 01:34 PM, AnilKumar Ch wrote:
> This patch fixes an interrupt thrash issue with c_can driver.
>
> In c_can_isr() function interrupts are disabled and enabled only in
> c_can_poll() function. c_can_isr() & c_can_poll() both read the
> irqstatus flag. However, irqstatus is always read as 0 in c_can_poll()
> because all C_CAN interrupts are disabled in c_can_isr(). This causes
> all interrupts to be re-enabled in c_can_poll() which in turn causes
> another interrupt since the event is not really handled. This keeps
> happening causing a flood of interrupts.
>
> To fix this, read the irqstatus register in isr and use the same cached
> value in the poll function.
>
> Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Can you or someone else please test this patch on c_can hardware, and
add her/his Tested-by? This patch is a stable candidate, isn't it?
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
cheers, Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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next prev parent reply other threads:[~2012-05-10 19:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-10 11:34 [PATCH v2 0/4] can: c_can: Add support for Bosch D_CAN controller AnilKumar Ch
2012-05-10 11:34 ` [PATCH v2 1/4] can: c_can: fix an interrupt thrash issue with c_can driver AnilKumar Ch
2012-05-10 19:13 ` Marc Kleine-Budde [this message]
2012-05-10 11:34 ` [PATCH v2 2/4] can: c_can: fix: enable CAN HW interrupts after napi_enable() AnilKumar Ch
2012-05-10 19:16 ` Marc Kleine-Budde
2012-05-11 11:09 ` AnilKumar, Chimata
2012-05-10 11:34 ` [PATCH v2 3/4] can: c_can: Move overlay structure to array with offset as index AnilKumar Ch
2012-05-10 20:12 ` Marc Kleine-Budde
2012-05-11 11:09 ` AnilKumar, Chimata
2012-05-11 14:40 ` Wolfgang Grandegger
2012-05-11 15:23 ` AnilKumar, Chimata
2012-05-11 16:54 ` Marc Kleine-Budde
2012-05-10 11:34 ` [PATCH v2 4/4] can: c_can: Add support for Bosch D_CAN controller AnilKumar Ch
2012-05-10 19:34 ` Marc Kleine-Budde
2012-05-11 11:10 ` AnilKumar, Chimata
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