From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>,
linux-kernel@vger.kernel.org, mingo@elte.hu, fweisbec@gmail.com,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
linux-acpi@vger.kernel.org, akpm@linux-foundation.org
Subject: Re: [PATCH 0/4] Fastboot revisited: Asynchronous function calls
Date: Sun, 4 Jan 2009 21:44:38 +0000 [thread overview]
Message-ID: <20090104214438.196ff4ff@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.00.0901041009060.3179@localhost.localdomain>
> I _think_ it's the irq auto-probing, but that's just a guess. The 8250
> driver does some historical crud, like
>
> probe_irq_off(probe_irq_on());
>
> to get rid of any pending irq's, but that should be entirely pointless
> these days. I bet that line basically goes back to pre-history, before we
> made the auto-probing much stabler.
For non ISA boxes we shouldn't be - but this old code. The IRQ for the
built in ports is defined by convention, in the BIOS PnP tables or with
ACPI in the ACPI tables. So we shouldn't even be autoprobing the IRQ.
We *do* have to wait one transmission timeout or so to detect buggy uarts
but in theory that could be moved down into the open path.
Alan
next prev parent reply other threads:[~2009-01-04 21:44 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-04 17:24 [PATCH 0/4] Fastboot revisited: Asynchronous function calls Arjan van de Ven
2009-01-04 17:28 ` [PATCH 1/4] fastboot: Asynchronous function calls to speed up kernel boot Arjan van de Ven
2009-01-04 18:33 ` Linus Torvalds
2009-01-04 18:40 ` Arjan van de Ven
2009-01-04 18:49 ` Arjan van de Ven
2009-01-04 19:05 ` Andi Kleen
2009-01-04 19:09 ` Arjan van de Ven
2009-01-04 19:49 ` Andi Kleen
2009-01-04 19:52 ` Andrew Morton
2009-01-04 17:29 ` [PATCH 2/4] fastboot: make scsi probes asynchronous Arjan van de Ven
2009-01-04 18:05 ` Matthew Wilcox
2009-01-04 18:13 ` Arjan van de Ven
2009-01-04 18:38 ` Jaswinder Singh Rajput
2009-01-04 18:44 ` Arjan van de Ven
2009-01-04 17:30 ` [PATCH 3/4] fastboot: make the libata port scan asynchronous Arjan van de Ven
2009-01-04 17:31 ` [PATCH 4/4] fastboot: make ACPI bus drivers probe asynchronous Arjan van de Ven
2009-01-05 2:03 ` Zhao Yakui
2009-01-05 1:58 ` Arjan van de Ven
2009-01-05 2:51 ` Zhao Yakui
2009-01-05 2:51 ` Arjan van de Ven
2009-01-05 5:30 ` Zhao Yakui
2009-01-04 18:16 ` [PATCH 0/4] Fastboot revisited: Asynchronous function calls Linus Torvalds
2009-01-04 18:31 ` Arjan van de Ven
2009-01-04 18:54 ` Linus Torvalds
2009-01-04 19:05 ` Arjan van de Ven
2009-01-04 19:11 ` Linus Torvalds
2009-01-04 19:19 ` Arjan van de Ven
2009-01-05 16:21 ` Alan Cox
2009-01-05 21:13 ` Arjan van de Ven
2009-01-05 21:21 ` Linus Torvalds
2009-01-04 19:11 ` Andi Kleen
2009-01-04 19:46 ` Robert Hancock
2009-01-04 19:27 ` Linus Torvalds
2009-01-04 19:48 ` Arjan van de Ven
2009-01-04 21:44 ` Alan Cox [this message]
2009-01-11 13:14 ` Pavel Machek
2009-01-05 6:01 ` Nigel Cunningham
2009-01-05 8:47 ` Frederic Weisbecker
2009-01-05 10:53 ` Arjan van de Ven
2009-01-05 11:18 ` Nigel Cunningham
2009-01-07 2:41 ` Shaohua Li
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