From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.stach@pengutronix.de (Lucas Stach) Date: Mon, 28 Sep 2015 10:15:30 +0200 Subject: [PATCH] Revert "serial: imx: remove unbalanced clk_prepare" In-Reply-To: References: <1439912592-14779-1-git-send-email-fabio.estevam@freescale.com> Message-ID: <1443428130.3178.3.camel@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Am Samstag, den 26.09.2015, 17:14 -0300 schrieb Fabio Estevam: > Hi Greg, > > On Tue, Aug 18, 2015 at 12:43 PM, Fabio Estevam > wrote: > > This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. > > > > Commit ("9e7b399d6528ea") causes the following warning and sometimes > > also hangs the system: > > > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() > > DEBUG_LOCKS_WARN_ON(in_interrupt()) > > Modules linked in: > > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 > > Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) > > Backtrace: > > [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) > > r6:00000364 r5:00000000 r4:00000000 r3:00000000 > > [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) > > [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) > > r5:807945c4 r4:80ab3b50 > > [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) > > r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 > > [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) > > r3:8095d0d8 r2:8095ab28 > > [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) > > r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 > > [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) > > r5:00000037 r4:be3f0c80 > > [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) > > r4:812d0bc8 r3:8132b9a4 > > > > To reproduce the problem we only need to let the board idle for something > > like 30 seconds. > > > > Tested on a imx6q-sabresd. > > > > Signed-off-by: Fabio Estevam > > Could you please consider applying this one for 4.3-rc? > To put a bit more wight behind this: without this revert i.MX6 with an active serial console boards are not even able to boot into userspace. Please apply this as a critical fix. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ |