linux-kernel - Re: [PATCH 0/1] Platform: x86: chromeos_laptop - convert to i2c

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

Message-ID: <CAC-DJzL0VzDxCpsdwjugavBhcFUr+kv+iN9D-Yz_tasw=DF75Q@mail.gmail.com>
Date:	Mon, 5 Aug 2013 07:32:43 +0200
From:	Martin Nordholts <enselic@...il.com>
To:	Benson Leung <bleung@...omium.org>
Cc:	Matthew Garrett <matthew.garrett@...ula.com>,
	Olof Johansson <olof@...om.net>,
	Yufeng Shen <miletus@...omium.org>,
	"platform-driver-x86@...r.kernel.org" 
	<platform-driver-x86@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/1] Platform: x86: chromeos_laptop - convert to
 i2c_driver to handle i915 race

2013/8/5 Benson Leung <bleung@...omium.org>:
> Hi Martin,
>
> Thank you for looking into this problem. Obviously, this is a problem
> Olof and our team has been working on as well.

Hi Benson,

Thank you for spending time reviewing and testing my patch. I
understand your team is busy and am honored you took the time to look
at my code.

> Your driver would result in three failed probes in 2 different drivers
> on my board.

Yes that is one down-side; sometimes the detect() function will be
triggered even though the device is not supported (the return -ENODEV
code paths in my driver). I thought that maybe a simpler driver could
make up for unnecessary detect() calls. However ...

> "Detect" is method #3, but it comes with a
> stern warning : Once again, method 3 should be avoided wherever
> possible. Explicit device instantiation (methods 1 and 2) is much
> preferred for it is safer and faster.

... I must admit I did not see this. I realize that this makes my
patch a dead end. I wish I would have seen that earlier, that would
have saved time for everyone. My apologies.

Regarding the interaction with non-i2c devices in chromeos_laptop, I
was thinking that could perhaps have been solved by putting the i2c
stuff in a separate driver, say chromeos_laptop_i2c, but that point is
irrelevant now that you pointed out that the use of the
detect()-method is discouraged by the documentation.

Thank you again for reviewing the patch and for providing feedback.

BR,
Martin
--
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/