From mboxrd@z Thu Jan 1 00:00:00 1970 From: marek.vasut@gmail.com (Marek Vasut) Date: Mon, 19 Dec 2011 22:43:49 +0100 Subject: [PATCH] MXS: Convert mutexes in clock.c to spinlocks In-Reply-To: <201112192237.42034.marek.vasut@gmail.com> References: <1324217174-6574-1-git-send-email-marek.vasut@gmail.com> <20111219212847.GK14542@n2100.arm.linux.org.uk> <201112192237.42034.marek.vasut@gmail.com> Message-ID: <201112192243.49355.marek.vasut@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > > On Mon, Dec 19, 2011 at 10:05:25PM +0100, Marek Vasut wrote: > > > > On Mon, Dec 19, 2011 at 09:54:25PM +0100, Marek Vasut wrote: > > > > > > So, in summary, you have everything you require to fix it outside > > > > > > the driver. You just have to decide which of the two options you > > > > > > want to proceed with, and actually (and finally) do it instead of > > > > > > endlessly procrastinating and waiting for more and more bug > > > > > > reports (which is exactly what has happened so far.) > > > > > > > > > > What the hell, I just recently found this bug and I submitted a > > > > > patch right away! What are you complaining about?! > > > > > > > > If you want to take that attitude to my attempt to help you > > > > understand the problem and see solutions, I'll ignore you > > > > permanently for being an absolute twit. > > > > > > Go ahead, but you accused me of procrastinating and waiting even if the > > > first thing I did when I saw the bug was start solving it. That's just > > > insane! > > > > > > > I'm not going to spend time giving a detailed explaination > > > > about the background and options over something to only then have it > > > > immediately shoved back in my face with such a response. > > > > > > I consider my response to the last part of your email appropriate. > > > > Sorry, it wasn't directed personally at you, but to the entire MXS > > > community. The facts over this are: > Ah! I'm sorry I was so direct and rude too. I was unaware it was discussed > before, I started this effort on my own just recently. > > > 1. This problem has been known about since October. > > I was really away from the kernel community for a while so I didn't know. > > > 2. It's been discussed several times - every time along the same lines. > > 3. There is zero apparant progress on the issue. > > > > Here's two of the discussions over it, where I've said exactly the same > > thing: > > > > http://lists.arm.linux.org.uk/lurker/thread/20111018.173744.46c4bd76.en.h > > tm l > > http://lists.arm.linux.org.uk/lurker/thread/20111123.183640.222b05cf.en.h > > t ml > > > > So now, tell me - is this _finally_ going to get fixed in the MXS code, > > or is the previous discussion about converting stuff to spinlocks etc > > just going to be repeated yet again? > > Spinlocks are OK as far as the code within them is fast, right ? But hm ... > actually, we might be able to toggle the clock in one instruction by using > the bitwise set/clear registers. That way, we won't need the locks at all, > but we'd loose the usecount ... which is useless anyway). > > M I see ... clk_set_rate() can be slow. OK, looking further into it. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753277Ab1LSVn4 (ORCPT ); Mon, 19 Dec 2011 16:43:56 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:33745 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752287Ab1LSVny (ORCPT ); Mon, 19 Dec 2011 16:43:54 -0500 From: Marek Vasut To: "Russell King - ARM Linux" Subject: Re: [PATCH] MXS: Convert mutexes in clock.c to spinlocks Date: Mon, 19 Dec 2011 22:43:49 +0100 User-Agent: KMail/1.13.7 (Linux/3.1.0-1-amd64; KDE/4.6.5; x86_64; ; ) Cc: Shawn Guo , Wolfgang Denk , Sascha Hauer , linux-kernel@vger.kernel.org, Huang Shijie , linux-arm-kernel@lists.infradead.org, Shawn Guo , Stefano Babic References: <1324217174-6574-1-git-send-email-marek.vasut@gmail.com> <20111219212847.GK14542@n2100.arm.linux.org.uk> <201112192237.42034.marek.vasut@gmail.com> In-Reply-To: <201112192237.42034.marek.vasut@gmail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201112192243.49355.marek.vasut@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > On Mon, Dec 19, 2011 at 10:05:25PM +0100, Marek Vasut wrote: > > > > On Mon, Dec 19, 2011 at 09:54:25PM +0100, Marek Vasut wrote: > > > > > > So, in summary, you have everything you require to fix it outside > > > > > > the driver. You just have to decide which of the two options you > > > > > > want to proceed with, and actually (and finally) do it instead of > > > > > > endlessly procrastinating and waiting for more and more bug > > > > > > reports (which is exactly what has happened so far.) > > > > > > > > > > What the hell, I just recently found this bug and I submitted a > > > > > patch right away! What are you complaining about?! > > > > > > > > If you want to take that attitude to my attempt to help you > > > > understand the problem and see solutions, I'll ignore you > > > > permanently for being an absolute twit. > > > > > > Go ahead, but you accused me of procrastinating and waiting even if the > > > first thing I did when I saw the bug was start solving it. That's just > > > insane! > > > > > > > I'm not going to spend time giving a detailed explaination > > > > about the background and options over something to only then have it > > > > immediately shoved back in my face with such a response. > > > > > > I consider my response to the last part of your email appropriate. > > > > Sorry, it wasn't directed personally at you, but to the entire MXS > > > community. The facts over this are: > Ah! I'm sorry I was so direct and rude too. I was unaware it was discussed > before, I started this effort on my own just recently. > > > 1. This problem has been known about since October. > > I was really away from the kernel community for a while so I didn't know. > > > 2. It's been discussed several times - every time along the same lines. > > 3. There is zero apparant progress on the issue. > > > > Here's two of the discussions over it, where I've said exactly the same > > thing: > > > > http://lists.arm.linux.org.uk/lurker/thread/20111018.173744.46c4bd76.en.h > > tm l > > http://lists.arm.linux.org.uk/lurker/thread/20111123.183640.222b05cf.en.h > > t ml > > > > So now, tell me - is this _finally_ going to get fixed in the MXS code, > > or is the previous discussion about converting stuff to spinlocks etc > > just going to be repeated yet again? > > Spinlocks are OK as far as the code within them is fast, right ? But hm ... > actually, we might be able to toggle the clock in one instruction by using > the bitwise set/clear registers. That way, we won't need the locks at all, > but we'd loose the usecount ... which is useless anyway). > > M I see ... clk_set_rate() can be slow. OK, looking further into it.