Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753303Ab3HVApQ (ORCPT ); Wed, 21 Aug 2013 20:45:16 -0400 Received: from mga09.intel.com ([134.134.136.24]:60106 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752740Ab3HVApP (ORCPT ); Wed, 21 Aug 2013 20:45:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,930,1367996400"; d="scan'208";a="391270470" Date: Wed, 21 Aug 2013 17:45:14 -0700 From: Sarah Sharp To: Julius Werner Cc: LKML , "linux-usb@vger.kernel.org" , Greg Kroah-Hartman , Vincent Palatin , Benson Leung , Felipe Balbi , mathias.nyman@linux.intel.com Subject: Re: [PATCH] usb: xhci-plat: Enable USB 2.0 hardware LPM support for platform xHCs Message-ID: <20130822004514.GB19747@xanatos> References: <1377040909-18428-1-git-send-email-jwerner@chromium.org> <20130821184042.GC3577@xanatos> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1818 Lines: 38 On Wed, Aug 21, 2013 at 02:43:55PM -0700, Julius Werner wrote: > > Thanks for the patch! Did you test with a USB analyzer to see if the > > device was actually going into USB 2.0 Link PM? I'd like to confirm we > > really aren't breaking anything for DW3 hosts by enabling this. > > Yes, I did. The LPM transfers on the analyzer look good and the device > works as expected. Ok, good to know. Greg, is your USB tree still open for feature requests? I wouldn't normally send you usb-next requests so late, but this is pretty simple patch to extend a feature that's already in your usb-next tree. > My platform only runs a 3.8 derivative, though, so I now have also > cherry-picked the BESL patches that went in since then to make sure > they don't break things. I had problems on one device until I found > the XHCI_BLC fix Mathias sent out this morning, so you should pick > that one up first. (Without it LPM doesn't break completely but seems > to assert resume for less time than the HIRD defines, so the device > sometimes gets confused and resets. I can't figure out how BESL is > really supposed to work since the XHCI spec from 8/14/12 where it's > supposedly defined doesn't seem to be publicly available.) You need the USB 2.0 spec errata from 2011-11 that describes the changes made for BESL as well. It's in the USB2-LPM-Errata-final.pdf and USB2_LinkPowerMangement_ECN[final].pdf files in this zip file: http://www.usb.org/developers/docs/usb_20_070113.zip I agree though, it's all a confusing mess for documentation on USB 2.0 Link PM. Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/