From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Shilimkar, Santosh) Date: Sat, 7 Jul 2012 17:58:40 +0530 Subject: [PATCH] Watchdog: OMAP: Fix the runtime pm code to avoid module getting stuck intransition state. In-Reply-To: <20120707122725.GY735@spo001.leaseweb.com> References: <1339996996-3257-1-git-send-email-lokeshvutla@ti.com> <20120707122725.GY735@spo001.leaseweb.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Jul 7, 2012 at 5:57 PM, Wim Van Sebroeck wrote: > > Hi All, > > > > On Mon, Jun 18, 2012 at 10:53 AM, Lokesh Vutla > > > wrote: > > >> OMAP watchdong driver is adapted to runtime PM like a general device > > >> driver but it is not appropriate. It is causing couple of functional > > >> issues. > > >> > > >> 1. On OMAP4 SYSCLK can't be gated, because of issue with WDTIMER2 > > >> module, > > >> which constantly stays in "in transition" state. Value of register > > >> CM_WKUP_WDTIMER2_CLKCTRL is always 0x00010000 in this case. > > >> Issue occurs immediately after first idle, when hwmod framework tries > > >> to disable WDTIMER2 functional clock - "wd_timer2_fck". After this > > >> module falls to "in transition" state, and SYSCLK gating is blocked. > > >> > > >> 2. Due to runtime PM, watchdog timer may be completely disabled. > > >> In current code base watchdog timer is not disabled only because of > > >> issue 1. Otherwise state of WDTIMER2 module will be "Disabled", and > > >> there > > >> will be no interrupts from omap_wdt. In other words watchdog will not > > >> work at all. > > >> > > >> Watchdong is a special IP and it should not be disabled otherwise > > >> purpose of it itself is defeated. Watchdog functional clock should > > >> never be disabled. This patch updates the runtime PM handling in > > >> driver so that runtime PM is limited only during probe/shutdown > > >> and suspend/resume. > > >> > > >> The patch fixes issue 1 and 2 > > >> > > >> Signed-off-by: Lokesh Vutla > > >> Acked-by: Santosh Shilimkar > > >> Cc: Wim Van Sebroeck > > >> --- > > > > Any comments on this patch ? If not, can you please > > queue this up for the 3.5-rc? > > Added to linux-watchdog-next. > Thanks Wim. Regards Santosh