From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: monstr@monstr.eu
Cc: linux-serial@vger.kernel.org, Greg Kroah-Hartman <gregkh@suse.de>,
LKML <linux-kernel@vger.kernel.org>,
Peter Korsgaard <jacmet@sunsite.dk>
Subject: Re: Using serial driver 16550A in poll mode without interrupt connected
Date: Wed, 12 Oct 2011 14:51:53 +0100 [thread overview]
Message-ID: <20111012145153.5490b592@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <4E95902B.7080204@monstr.eu>
> Driver is probed with no IRQ (NO_IRQ = -1 on Microblaze)
> 83e00000.serial: ttyS0 at MMIO 0x83e01003 (irq = -1) is a 16550A
Zero means no IRQ. NO_IRQ is a legacy internal thing for the old IDE code
so not something other code should be using. Setting the IRQ to -1 is
bogus and will confuse the rest of the kernel.
> Is it possible to use serial driver without IRQ - or blocking IRQ, etc.?
Within limits - it kills your power management and data rates because of
the continual polling.
Alan
next prev parent reply other threads:[~2011-10-12 13:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-12 13:03 Michal Simek
2011-10-12 13:51 ` Alan Cox [this message]
2011-10-12 15:19 ` Ted Ts'o
2011-10-13 10:08 ` Michal Simek
2011-10-13 9:56 ` Michal Simek
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