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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Min Zhang <mzhang@mvista.com>
Cc: gregkh@linuxfoundation.org, linux-serial@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] serial: 8250 check iir rdi in interrupt
Date: Tue, 23 Oct 2012 11:01:33 +0100	[thread overview]
Message-ID: <20121023110133.62bed522@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.02.1210221633450.28146@nightowl>

> Added module parameter skip_rdi_check to opt out this workaround.

NAK. Anything like this should be runtime.

> Tested on Radisys ATCA 46XX which uses FPGA 16550-compatible and
> other generic 16550 UART. It takes from an hour to days to reproduce by
> pumping inputs to serial console continously using TeraTerm script:

You turn this on by default but it's a nasty IRQ latency penalty
on a lot of x86 platforms with the uarts on the lpc bus.

What I am not clear on from this is

- do you see it on both the ports (the bug that is)
- if you do see it on both are you sure its not in reality a symptom of
  some other console/irq handling race ?

Alan

  reply	other threads:[~2012-10-23  9:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-23  0:19 [PATCH] serial: 8250 check iir rdi in interrupt Min Zhang
2012-10-23 10:01 ` Alan Cox [this message]
2012-10-23 19:43   ` Min Zhang
2012-10-26 14:19     ` Alan Cox
2012-10-26 21:57       ` Min Zhang
2012-10-30 14:24         ` Alan Cox
2012-10-26 22:16       ` [PATCHv2] " Min Zhang

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