From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Shilimkar, Santosh) Date: Wed, 4 Jul 2012 21:32:21 +0530 Subject: [PATCH] Watchdog: OMAP: Fix the runtime pm code to avoid module getting stuck intransition state. In-Reply-To: References: <1339996996-3257-1-git-send-email-lokeshvutla@ti.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Wim, On Mon, Jun 18, 2012 at 11:11 AM, Shilimkar, Santosh wrote: > (You should cc linux-omap too. CC'ing linux-omap) > > 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? Regards Santosh