linux-kernel - Re: [PATCH] [mmc] [tifm] Reduces delay in card insert/removal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <200704260100.31035.arnd@arndb.de>
Date:	Thu, 26 Apr 2007 01:00:30 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	Sergey Yanovich <ynvich@...il.com>
Cc:	linux-kernel@...r.kernel.org, drzeus-mmc@...eus.cx
Subject: Re: [PATCH] [mmc] [tifm] Reduces delay in card insert/removal

On Wednesday 25 April 2007, Sergey Yanovich wrote:

> First, I tried to replace 'mdelay' with 'msleep' and put it after
> 'unlock'. It gives a certain oops.
> 
> With the delay of 50 msec driver remains stable. It has something
> to do with hardware initialization, so this value should not be
> affected by CPU speed. I hope so.
> 
> Signed-off-by: Sergey Yanovich <ynvich@...il.com>

No, 50ms is still too much, I'd consider every instance of 'mdelay'
to be a bug in general, except maybe with exceptionally broken
hardware, which I don't think this is.

The reason that it gave you an oops is that you call it from
a tasklet. You have to convert the tasklet to a workqueue at the
same time if you want to sleep inside it. In fact, it might
be a good idea to convert all the tasklets in that driver
to use schedule_work instead.

	Arnd <><
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/