From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Gerlach Subject: Re: [PATCH] ARM: dts: am437x-gp-evm: Boot fixes Date: Tue, 22 Apr 2014 14:53:18 -0500 Message-ID: <5356C8AE.3090907@ti.com> References: <1398192739-8901-1-git-send-email-d-gerlach@ti.com> <20140422190132.GA12204@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:57452 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756639AbaDVTxn (ORCPT ); Tue, 22 Apr 2014 15:53:43 -0400 In-Reply-To: <20140422190132.GA12204@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, Rajendra Nayak , Nishanth Menon , bcousson@baylibre.com, Sekhar Nori , Lokesh Vutla On 04/22/2014 02:01 PM, Tony Lindgren wrote: > * Dave Gerlach [140422 11:52]: >> This patch, along with patch here [1], fixes boot for am437x-gp-evm. The >> bootloader configures gpio5_7 to control the DDR3 termination regulator, >> the linked patch prevents that gpio bank from being reset and losing >> the previously configured state, and this patch binds the gpio to a >> regulator so the kernel is aware of the state of the gpio. >> >> [1] https://www.mail-archive.com/linux-omap@vger.kernel.org/msg102941.html > > Setting up the GPIO regulator makes sense to me. But the hack in the > link above is potentially a nasty time bomb for anybody trying to > use GPIO bank 5 on that board. > > What tests have been done that the GPIO bank behaves properly when > it's not reset? We've been using this configuration on this board for a while without any apparent issues. Also, am335x-evmsk already uses the same idea for the VTT regulator on board from commit 6046adb6ad701026c10adeac8d6a4138895f12e5 [ARM: dts: am335x-evmsk: Do not reset gpio0] and I am unaware of any issues with that either. Regards, Dave > > Regards, > > Tony > From mboxrd@z Thu Jan 1 00:00:00 1970 From: d-gerlach@ti.com (Dave Gerlach) Date: Tue, 22 Apr 2014 14:53:18 -0500 Subject: [PATCH] ARM: dts: am437x-gp-evm: Boot fixes In-Reply-To: <20140422190132.GA12204@atomide.com> References: <1398192739-8901-1-git-send-email-d-gerlach@ti.com> <20140422190132.GA12204@atomide.com> Message-ID: <5356C8AE.3090907@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/22/2014 02:01 PM, Tony Lindgren wrote: > * Dave Gerlach [140422 11:52]: >> This patch, along with patch here [1], fixes boot for am437x-gp-evm. The >> bootloader configures gpio5_7 to control the DDR3 termination regulator, >> the linked patch prevents that gpio bank from being reset and losing >> the previously configured state, and this patch binds the gpio to a >> regulator so the kernel is aware of the state of the gpio. >> >> [1] https://www.mail-archive.com/linux-omap at vger.kernel.org/msg102941.html > > Setting up the GPIO regulator makes sense to me. But the hack in the > link above is potentially a nasty time bomb for anybody trying to > use GPIO bank 5 on that board. > > What tests have been done that the GPIO bank behaves properly when > it's not reset? We've been using this configuration on this board for a while without any apparent issues. Also, am335x-evmsk already uses the same idea for the VTT regulator on board from commit 6046adb6ad701026c10adeac8d6a4138895f12e5 [ARM: dts: am335x-evmsk: Do not reset gpio0] and I am unaware of any issues with that either. Regards, Dave > > Regards, > > Tony >