From: Anssi Hannula <anssi.hannula@gmail.com>
To: Ben Gamari <ben@mw0.ath.cx>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Andrey Borzenkov <arvidjaar@mail.ru>,
Kay Sievers <kay.sievers@vrfy.org>, Greg KH <greg@kroah.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [2.6.23-rc9 regression] commit 4f01a757 broke HAL input support
Date: Fri, 05 Oct 2007 14:36:09 +0300 [thread overview]
Message-ID: <470621A9.10004@gmail.com> (raw)
In-Reply-To: <1191557863.6579.0.camel@mercury>
Ben Gamari wrote:
> On Thu, 2007-10-04 at 22:40 -0400, Dmitry Torokhov wrote:
>> 4f01a757e75f2a3cab2bab89c4176498963946b9.
>
> The change that Dmitry proposed would still require
> CONFIG_SYSFS_DEPRECATED, right?
What proposed change?
The changeset you quote is already applied.
Andrey Borzenkov wrote:
>> Actually this specific problem was introduced by
>> 4f01a757e75f2a3cab2bab89c4176498963946b9. This commit seems to have
>> completely disassociated eventX from corresponding inputY
>>
>> To summarize.
>>
>> 1. Any kernel with SYSFS_DEPRECATED unset
>>
>> events are sent for /devices/...
>> /devices/.../eventX is direct child of /devices/.../inputY
>> HAL checks for parent of eventX, finds inputY and is happy
>>
>> 2. SYSFS_DEPRECATED=y, pre-2.6.23 kernel
>>
>> events are sent for /class/...
>> /class/.../eventX is direct child of /class/.../inputY
>> HAL checks for parent of eventX, finds inputY and works
>>
>> 3. SYSFS_DEPRECATED=y, 2.6.23 before commit
>> 4f01a757e75f2a3cab2bab89c4176498963946b9.
>>
>> events are sent for /class/...
>> /class/.../eventX is *not* child of /class/.../inputY
>> /class/.../eventX/device points to .../inputY
>> HAL checks for .../device link, finds inputY and works
>>
>> 4. SYSFS_DEPRECATED=y, 2.6.23 after commit
>> 4f01a757e75f2a3cab2bab89c4176498963946b9.
>>
>> /class/.../eventX is *not* child of /class/.../inputY
>> /class/.../eventX/device points to some physical device
>> HAL finds inputY neither as ../inputY nor as device link and breaks
>>
>> But what is worse, now the only way to find which inputY corresponds to which
>> eventX is to scan the whole /class/input, check for device link and compare.
>> I am afraid that we have to bite the bullet and just accept that 2.6.23 breaks
>> user space this way or that. Frankly fixing path_id seems to be the least
>> evil.
I'd hate to see such breakage. IMO the sysfs structure of input devices
should be made compatible with both HAL and udev, with both
CONFIG_SYSFS_DEPRECATED and without it, as in 2.6.22 and before.
>> Is it possible to fall back to /class/input/inputX/eventY if SYSFS_DEPRECATED
>> is set?
Hopefully.
--
Anssi Hannula
parent reply other threads:[~2007-10-05 11:37 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <1191557863.6579.0.camel@mercury>]
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