From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] tty: serial: 8250: omap: Add pinctrl support for suspend Date: Thu, 6 Nov 2014 12:35:44 -0800 Message-ID: <20141106203544.GE31454@atomide.com> References: <1415300850-21452-1-git-send-email-bigeasy@linutronix.de> <545BC8C1.4070503@ti.com> <545BCF3F.8020705@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:29728 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750846AbaKFUgm (ORCPT ); Thu, 6 Nov 2014 15:36:42 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Nishanth Menon Cc: Sebastian Andrzej Siewior , linux-serial@vger.kernel.org, Greg Kroah-Hartman , linux-omap , Dave Gerlach * Nishanth Menon [141106 11:59]: > On Thu, Nov 6, 2014 at 1:42 PM, Sebastian Andrzej Siewior > wrote: > > On 11/06/2014 08:15 PM, Nishanth Menon wrote: > >> sounds good to me *IF* omap8250_enable_wakeup (wakeirq handling) is > >> the way we want to continue doing things for daisychain? -> Tony, can > >> you comment? > >> http://marc.info/?l=linux-omap&m=141222144402707&w=2 > >> > >> I wonder if wakeirq explicit handling is valid anymore and something > >> given the potential race and alternate approach proposed? > > > > The wakeirq logic is already in the driver. So if we go for the > > alternate approach, the pinctrl patch is obsolete? Or does it mean we > > get rid of the map8250_enable_wakeup() including the second irq we have > > now (and keep the pinctl change)? > > based on Thomas's feedback we should probably not carry forward > wakeirq as a seperate irq with it's own request_irq instead it psuedo > triggers uart's interrupt irq -> I am not clear about the direction The pinctrl change in this patch and the wake-up events are a separate issue. As some omaps need the RX pin remuxed temporarily to GPIO for wake-up events, the $subject patch seems just fine to me. For the wake-up interrupts, the issue Thomas was concerned was re-entrant interrupts and handling the wake-up interrupts in various different ways. From hardware point of view the wake-up events behave like a separate IRQ controller, so the request_irq part is fine. > Tony wants drivers to take in the approach in the thread above - all I > wondered was if it had any conflict of pin_sleep -> if the generic > handler retriggers the irq before the suspend_handler, then > configuring sleep is gonna break daisychain support. not sure if there > is any specific direction drivers should take. The wake-irq is disabled during runtime and should be enabled so that should not be an issue. > Again, Tony is the right guy to comment about this. Yeah I'll repost the patches for the generic wake-irq handling. Fixing up the drivers to use that is trivial once we've agreed on the generic wake-up event handling. Regards, Tony