From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E1A8CA9EC2 for ; Mon, 28 Oct 2019 16:55:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33B6E21721 for ; Mon, 28 Oct 2019 16:55:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572281713; bh=jckPOOiYQQNbkLKnA5USZLqd3mccflwO5hFc1CWTZjk=; h=Subject:To:From:Date:List-ID:From; b=YFzA0t7/3Wn1PyS2l2FfNJBeTG1h8pSEyQhs8Ia1MhtoEJCE5m80McChEG7IURxvP 3lSlZnEj6T1VcIsRHfRK4I1HCUg9WTnXLMysmZvIgYmI7ENKThh+366WOjRBC4fhm7 eelWblfPawD51pHde1OANnJqK2XPm2yKuQC2is0s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730550AbfJ1QzM (ORCPT ); Mon, 28 Oct 2019 12:55:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:52788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726234AbfJ1QzM (ORCPT ); Mon, 28 Oct 2019 12:55:12 -0400 Received: from localhost (100.50.158.77.rev.sfr.net [77.158.50.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 254BC21744; Mon, 28 Oct 2019 16:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572281711; bh=jckPOOiYQQNbkLKnA5USZLqd3mccflwO5hFc1CWTZjk=; h=Subject:To:From:Date:From; b=DrakwDmPVGvPpS+NZEoLe+45130g29H2IF/mVT4Q6i9oTBiNclbxhEZlLGQng0mkK fDBFvMHW0cigXiMbxADLOIWtlp0gsYiB+0mMRWLLUvFRHGWh1c53+/hiH3reqUeYEz THoj803RVwWdp7wiIzZ8lYlT3gYaXi/2vBZiz/EE= Subject: patch "UAS: Revert commit 3ae62a42090f ("UAS: fix alignment of" added to usb-linus To: stern@rowland.harvard.edu, gregkh@linuxfoundation.org, hch@lst.de, oneukum@suse.com, stable@vger.kernel.org From: Date: Mon, 28 Oct 2019 17:55:04 +0100 Message-ID: <157228170448175@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled UAS: Revert commit 3ae62a42090f ("UAS: fix alignment of to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 1186f86a71130a7635a20843e355bb880c7349b2 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 23 Oct 2019 11:34:33 -0400 Subject: UAS: Revert commit 3ae62a42090f ("UAS: fix alignment of scatter/gather segments") Commit 3ae62a42090f ("UAS: fix alignment of scatter/gather segments"), copying a similar commit for usb-storage, attempted to solve a problem involving scatter-gather I/O and USB/IP by setting the virt_boundary_mask for mass-storage devices. However, it now turns out that the analogous change in usb-storage interacted badly with commit 09324d32d2a0 ("block: force an unlimited segment size on queues with a virt boundary"), which was added later. A typical error message is: ehci-pci 0000:00:13.2: swiotlb buffer is full (sz: 327680 bytes), total 32768 (slots), used 97 (slots) There is no longer any reason to keep the virt_boundary_mask setting in the uas driver. It was needed in the first place only for handling devices with a block size smaller than the maxpacket size and where the host controller was not capable of fully general scatter-gather operation (that is, able to merge two SG segments into a single USB packet). But: High-speed or slower connections never use a bulk maxpacket value larger than 512; The SCSI layer does not handle block devices with a block size smaller than 512 bytes; All the host controllers capable of SuperSpeed operation can handle fully general SG; Since commit ea44d190764b ("usbip: Implement SG support to vhci-hcd and stub driver") was merged, the USB/IP driver can also handle SG. Therefore all supported device/controller combinations should be okay with no need for any special virt_boundary_mask. So in order to head off potential problems similar to those affecting usb-storage, this patch reverts commit 3ae62a42090f. Signed-off-by: Alan Stern CC: Oliver Neukum CC: Acked-by: Christoph Hellwig Fixes: 3ae62a42090f ("UAS: fix alignment of scatter/gather segments") Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1910231132470.1878-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/uas.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index bf80d6f81f58..34538253f12c 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -789,29 +789,9 @@ static int uas_slave_alloc(struct scsi_device *sdev) { struct uas_dev_info *devinfo = (struct uas_dev_info *)sdev->host->hostdata; - int maxp; sdev->hostdata = devinfo; - /* - * We have two requirements here. We must satisfy the requirements - * of the physical HC and the demands of the protocol, as we - * definitely want no additional memory allocation in this path - * ruling out using bounce buffers. - * - * For a transmission on USB to continue we must never send - * a package that is smaller than maxpacket. Hence the length of each - * scatterlist element except the last must be divisible by the - * Bulk maxpacket value. - * If the HC does not ensure that through SG, - * the upper layer must do that. We must assume nothing - * about the capabilities off the HC, so we use the most - * pessimistic requirement. - */ - - maxp = usb_maxpacket(devinfo->udev, devinfo->data_in_pipe, 0); - blk_queue_virt_boundary(sdev->request_queue, maxp - 1); - /* * The protocol has no requirements on alignment in the strict sense. * Controllers may or may not have alignment restrictions. -- 2.23.0