From mboxrd@z Thu Jan 1 00:00:00 1970 From: valentin.longchamp@epfl.ch (Valentin Longchamp) Date: Wed, 02 Dec 2009 09:43:03 +0100 Subject: USB support on i.MX27 In-Reply-To: <37367b3a0912010651s2f7b6d0csc8fc73e088195697@mail.gmail.com> References: <37367b3a0911240343u58e3b3d2le5d48e638348a3ad@mail.gmail.com> <20091127101654.GP14091@buzzloop.caiaq.de> <37367b3a0911300707l2abafe3buf99f624c3c90b99@mail.gmail.com> <37367b3a0911301157k2a15cb80q5624cbd3f96063b8@mail.gmail.com> <37367b3a0912010616r26ff385bqe6b85db1c510822f@mail.gmail.com> <20091201142609.GP14091@buzzloop.caiaq.de> <37367b3a0912010651s2f7b6d0csc8fc73e088195697@mail.gmail.com> Message-ID: <4B162897.1080402@epfl.ch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Daniel and Alan, Alan Carvalho de Assis wrote: > Hi Daniel, > > On 12/1/09, Daniel Mack wrote: >> Hmm, I don't follow. You added some debug output and it started working, >> is that what you say? Do we possibly need memory barriers somewhere? >> > > Basically it, but I will do more tests to isolate the issue. > > In fact there is a board where the issue remain, but using old kernel > (2.6.22) both work. I am also investigating this issue. The same happens sometimes with my USB host with ULPI-ISP1504, but it never happens with the USB slave with the exact same hardware ULPI-ISP1504, that's why I have the feeling that it's a purely software issue. I also had the feeling that it was a timing issue (maybe with a clock not ready at the right time) and what I read from Alan comforts me with this feeling. But I haven't been able to isolate this either. Best Regards Val -- Valentin Longchamp, PhD Student, EPFL-STI-LSRO1 valentin.longchamp at epfl.ch, Phone: +41216937827 http://people.epfl.ch/valentin.longchamp MEA3485, Station 9, CH-1015 Lausanne