From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anders Roxell Subject: Re: [PATCH] drivers: i2c: exynos5: irq spinlock rt-safe Date: Mon, 31 Aug 2015 23:28:44 +0200 Message-ID: <20150831212844.GI13774@localhost.localdomain> References: <1440489125-20082-1-git-send-email-anders.roxell@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: kgene-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, ch.naveen-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, khilman-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-rt-users-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thomas Gleixner Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rt-users.vger.kernel.org On 2015-08-25 23:51, Thomas Gleixner wrote: > On Tue, 25 Aug 2015, Anders Roxell wrote: > > > The exynos5_i2c_message_start enables interrupts while holding the i2c > > lock which is sought by the irq handler. If an IRQ is received before > > this lock is released then a deadlock occurs. > > That's crap. The interrupt handler runs in an irq thread as RT forces > all normal interrupts to that. You are right, I will send a v2 with a better changelog. Cheers, Anders