From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [PATCH 1/1] mfd: omap-usb-host: Fix USB device detection problems on OMAP4 Panda Date: Mon, 02 Dec 2013 13:01:51 +0100 Message-ID: <529C76AF.10106@linutronix.de> References: <1385730118-26402-1-git-send-email-rogerq@ti.com> <1385730118-26402-2-git-send-email-rogerq@ti.com> <529C55DF.3000808@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <529C55DF.3000808@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Roger Quadros Cc: Michael Trimarchi , Felipe Balbi , lee.jones@linaro.org, sameo@linux.intel.com, tomi.valkeinen@ti.com, Stefan Roese , ljkenny.mailinglists@gmail.com, Linux OMAP Mailing List , USB list , linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org - stable@vger.kernel.org since they probably don't care about this unless the patch is merged. On 12/02/2013 10:41 AM, Roger Quadros wrote: > Michael, > > On 11/29/2013 05:32 PM, Michael Trimarchi wrote: >> Hi Roger >> >> On Fri, Nov 29, 2013 at 2:01 PM, Roger Quadros wrote: >>> With u-boot 2013.10, USB devices are sometimes not detected >>> on OMAP4 Panda. To make us independent of what bootloader does >>> with the USB Host module, we must RESET it to get it to a known >>> good state. This patch Soft RESETs the USB Host module. >>> >> >> Do you think that we need something similar of usb musb? >> I have seen the OTG_SYSCONFIG is touched in uboot and >> only readed in omap2430.c. > > I'm not sure about musb. Maybe Sebastian/Felipe have better idea. > In general I believe that all modules must be reset by the kernel. > based on the code at the bottom it touches the first few register(s) sysconfig. Isn't hwmod actually doing this idle stuff and resting the device during boot? > cheers, > -roger >> Sebastian