Message-ID: <4B5CDB53.6030009@iki.fi>
Date: Mon, 25 Jan 2010 01:44:19 +0200
From: Antti Palosaari <crope@iki.fi>
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To: Jiri Slaby <jslaby@suse.cz>
CC: mchehab@infradead.org, linux-kernel@vger.kernel.org, jirislaby@gmail.com,
       Mauro Carvalho Chehab <mchehab@redhat.com>, linux-media@vger.kernel.org
Subject: Re: [PATCH 1/1] media: dvb-usb/af9015, fix disconnection crashes
References: <1264007972-6261-1-git-send-email-jslaby@suse.cz>
In-Reply-To: <1264007972-6261-1-git-send-email-jslaby@suse.cz>
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On 01/20/2010 07:19 PM, Jiri Slaby wrote:
> When both remote controller and receiver intfs are handled by
> af9015, .probe do nothing for remote intf, but when .disconnect
> is called for both of them it touches intfdata every time. For
> remote it crashes obviously (as intfdata are unset).
>
> Altough there is test against data being NULL, it is not enough.
> It is because someone before us does not set intf drvdata to
> NULL. (In this case the hid layer.) But we cannot rely on intf
> being NULL anyway.
>
> Fix that by checking bInterfaceNumber in af9015_usb_device_exit
> and do actually nothing if it is not 0.

I was a little bit surprised when saw this error, why it haven't 
detected earlier. When I initially added interface check for .probe it 
was surely needed, it was creating two instances without that check in 
that time. When I now test this patch with debugs enabled I don't see 
.probe and .disconnect be called for this HID interface (interface 1) at 
all and thus checks not needed. I have Fedora Kernel 2.6.31.12 running 
with latest v4l-dvb. Is there now some kind of check added recently 
which blocks .probe and disconnect from HID interface?

regards
Antti
-- 
http://palosaari.fi/
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