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From: Tony Lindgren <tony@atomide.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: Peter Hurley <peter@hurleysoftware.com>,
	gregkh@linuxfoundation.org, vinod.koul@intel.com,
	dan.j.williams@intel.com, bigeasy@linutronix.de, nsekhar@ti.com,
	peter.ujfalusi@ti.com, dmaengine@vger.kernel.org,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/4] serial: omap: robustify for high speed transfers
Date: Thu, 11 Feb 2016 13:00:50 -0800	[thread overview]
Message-ID: <20160211210050.GY19432@atomide.com> (raw)
In-Reply-To: <87wpqbihel.fsf@linutronix.de>

Hi,

* John Ogness <john.ogness@linutronix.de> [160211 04:04]:
> 
> At these speeds, nearly every DMA interrupt is accompanied by a spurious
> UART interrupt. So, sadly, the interrupts are doubled.
> 
> It is on my TODO list to verify if the spurious UART interrupts exactly
> match the recently added [0] spurious interrupt detection in omap-intc.

If you're seeing spurious interrupts you may want try adding
a flush of posted write at the end of the 8250_omap interrupt
handler. Basically read back some register from the 8250. This
has fixed so far pretty much all the spurious IRQ issues for
omaps using the drivers/irqchip/irq-omap-intc.c, meaning omap3
and am335x and ti81xx variants too most likely.

Regards,

Tony

  reply	other threads:[~2016-02-11 21:00 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-22 10:27 [PATCH 0/4] serial: omap: robustify for high speed transfers John Ogness
2016-01-25 18:56 ` Peter Hurley
2016-01-29 16:35   ` John Ogness
2016-02-03  1:21     ` Peter Hurley
2016-02-11 12:02       ` John Ogness
2016-02-11 21:00         ` Tony Lindgren [this message]
2016-02-22 15:30           ` John Ogness
2016-02-22 19:38             ` Tony Lindgren
2016-02-23  9:59             ` Sekhar Nori
2016-02-23 12:43               ` Sebastian Andrzej Siewior
2016-02-23 16:56                 ` Andy Shevchenko
2016-02-24  3:20               ` Peter Hurley
2016-02-24 15:37                 ` Sekhar Nori
2016-02-24 15:46                   ` Sebastian Andrzej Siewior
2016-03-07 20:23                   ` Peter Hurley

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