Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965608AbbDWOJX (ORCPT ); Thu, 23 Apr 2015 10:09:23 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:34520 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934041AbbDWOJQ (ORCPT ); Thu, 23 Apr 2015 10:09:16 -0400 From: Johan Hovold To: Greg Kroah-Hartman , Felipe Balbi , Alan Stern Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Stephen Warren , Thierry Reding , Alexandre Courbot , linux-tegra@vger.kernel.org, Johan Hovold Subject: [PATCH v2 0/3] USB: fix inefficient copy of unaligned buffers Date: Thu, 23 Apr 2015 16:06:49 +0200 Message-Id: <1429798012-21916-1-git-send-email-johan@kernel.org> X-Mailer: git-send-email 2.0.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1930 Lines: 51 These patches (for 4.1) make sure that only the received data is copied from the temporary buffers used for unaligned transfers. I discovered this when debugging an issue where the Beaglebone Black would lock up on disconnect. Turns out it was related to the transfer_buffers not being properly aligned, causing musb to use temporary buffers for the transfers. On transfer errors (e.g. during disconnect), the full buffer content was still being copied, something which would alter timings enough to prevent the disconnect from being detected and processed. The first patch in the series works around the problem in that particular set up, but obviously does not solve the underlying issue, which needs to be analysed further. I also included a corresponding patch for ehci-tegra that has been compile tested only. Note that the octeon-hcd driver in staging, which also uses temporary buffers for unaligned transfers, was broken for isochronous transfers. The third patch fixes that, but is also untested due to lack of hardware. Johan v2: - Make sure to copy the full buffer for isochronous transfers, in which case the received data is not necessarily contiguous (thanks Alan). - Drop stable tags as this is really just an optimisation. Johan Hovold (3): USB: musb: fix inefficient copy of unaligned buffers USB: ehci-tegra: fix inefficient copy of unaligned buffers staging: octeon-usb: fix unaligned isochronous transfers drivers/staging/octeon-usb/octeon-hcd.c | 12 +++++++++--- drivers/usb/host/ehci-tegra.c | 12 +++++++++--- drivers/usb/musb/musb_host.c | 9 +++++++-- 3 files changed, 25 insertions(+), 8 deletions(-) -- 2.0.5 -- 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/