From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Karol Kozimor <sziwan@hell.org.pl>
Cc: linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] Convert serial_core oopses to BUG_ON
Date: Sun, 26 Feb 2006 22:41:45 +0000 [thread overview]
Message-ID: <20060226224145.GE31256@flint.arm.linux.org.uk> (raw)
In-Reply-To: <20060226223448.GA27562@hell.org.pl>
On Sun, Feb 26, 2006 at 11:34:48PM +0100, Karol Kozimor wrote:
> Thus wrote Russell King:
> > > > Calling serial functions to flush buffers, or try to send more data
> > > > after the port has been closed or hung up is a bug in the code doing
> > > > the calling, not in the serial_core driver.
> > > >
> > > > Make this explicitly obvious by adding BUG_ON()'s.
> > >
> > > If we make it
> > >
> > > if (!info) {
> > > WARN_ON(1);
> > > return;
> > > }
> > >
> > > will that allow people's kernels to limp along until it gets fixed?
> > "until" - I think you mean "if anyone ever bothers" so no I don't agree.
>
> Russel, I agree this should be clearly marked and an oops seems okay here,
> but we're talking dead systems here (dead as in all interrupts masked type
> of dead). Most users won't even be aware an oops occured, let alone be able
> to read the messages on the console.
>
> I was just lucky because after the first one I got (#5958, a regular oops)
> I tried to nail it down in text mode, with the console loglevel upped a
> bit, so I was able to see what the panic (#6131) was all about.
>
> I think we really need those *_ON()s at least in uart_write().
I don't think it'll make a blind bit of difference. The oopses have
been known about (to me and others) since about October 2005... Pavel
Machek was the first to report the hci_uart problems.
I diagnosed the uart_flush_buffer() oops being caused by hci_uart back
in October and where did that get us - nowhere at the time, but later
another bug report in bugzilla against serial and no progress.
Excuse me if I'm despondent on this issue - I'm personally looking for
a way out of being assigned blame for the crap known as hci_uart.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2006-02-26 22:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5Kr1a-6MF-15@gated-at.bofh.it>
[not found] ` <5KraE-6XP-15@gated-at.bofh.it>
[not found] ` <5KyFv-RL-15@gated-at.bofh.it>
2006-02-26 22:34 ` [PATCH] Convert serial_core oopses to BUG_ON Karol Kozimor
2006-02-26 22:41 ` Russell King [this message]
[not found] <20060227162827.GC2389@ucw.cz>
2006-03-01 19:00 ` Pavel Machek
2006-02-26 10:05 Russell King
2006-02-26 10:14 ` Andrew Morton
2006-02-26 10:18 ` Nick Piggin
2006-02-26 18:17 ` Russell King
2006-02-26 20:00 ` Russell King
2006-02-27 14:13 ` Pavel Machek
2006-02-28 18:17 ` Andrew Morton
2006-02-28 22:01 ` Martin Michlmayr
2006-02-28 23:32 ` Andrew Morton
2006-03-01 17:10 ` Russell King
2006-03-01 19:47 ` Pavel Machek
2006-03-01 22:32 ` Andrew Morton
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