Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933086AbdC1NoJ (ORCPT ); Tue, 28 Mar 2017 09:44:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59204 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753387AbdC1MfS (ORCPT ); Tue, 28 Mar 2017 08:35:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Samuel Thibault , Alan Stern Subject: [PATCH 4.4 28/76] usb-core: Add LINEAR_FRAME_INTR_BINTERVAL USB quirk Date: Tue, 28 Mar 2017 14:30:25 +0200 Message-Id: <20170328122601.116814122@linuxfoundation.org> X-Mailer: git-send-email 2.12.1 In-Reply-To: <20170328122559.966310440@linuxfoundation.org> References: <20170328122559.966310440@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2840 Lines: 83 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Samuel Thibault commit 3243367b209faed5c320a4e5f9a565ee2a2ba958 upstream. Some USB 2.0 devices erroneously report millisecond values in bInterval. The generic config code manages to catch most of them, but in some cases it's not completely enough. The case at stake here is a USB 2.0 braille device, which wants to announce 10ms and thus sets bInterval to 10, but with the USB 2.0 computation that yields to 64ms. It happens that one can type fast enough to reach this interval and get the device buffers overflown, leading to problematic latencies. The generic config code does not catch this case because the 64ms is considered a sane enough value. This change thus adds a USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL quirk to mark devices which actually report milliseconds in bInterval, and marks Vario Ultra devices as needing it. Signed-off-by: Samuel Thibault Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 10 ++++++++++ drivers/usb/core/quirks.c | 8 ++++++++ include/linux/usb/quirks.h | 6 ++++++ 3 files changed, 24 insertions(+) --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -246,6 +246,16 @@ static int usb_parse_endpoint(struct dev /* * Adjust bInterval for quirked devices. + */ + /* + * This quirk fixes bIntervals reported in ms. + */ + if (to_usb_device(ddev)->quirks & + USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) { + n = clamp(fls(d->bInterval) + 3, i, j); + i = j = n; + } + /* * This quirk fixes bIntervals reported in * linear microframes. */ --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -170,6 +170,14 @@ static const struct usb_device_id usb_qu /* M-Systems Flash Disk Pioneers */ { USB_DEVICE(0x08ec, 0x1000), .driver_info = USB_QUIRK_RESET_RESUME }, + /* Baum Vario Ultra */ + { USB_DEVICE(0x0904, 0x6101), .driver_info = + USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL }, + { USB_DEVICE(0x0904, 0x6102), .driver_info = + USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL }, + { USB_DEVICE(0x0904, 0x6103), .driver_info = + USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL }, + /* Keytouch QWERTY Panel keyboard */ { USB_DEVICE(0x0926, 0x3333), .driver_info = USB_QUIRK_CONFIG_INTF_STRINGS }, --- a/include/linux/usb/quirks.h +++ b/include/linux/usb/quirks.h @@ -50,4 +50,10 @@ /* device can't handle Link Power Management */ #define USB_QUIRK_NO_LPM BIT(10) +/* + * Device reports its bInterval as linear frames instead of the + * USB 2.0 calculation. + */ +#define USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL BIT(11) + #endif /* __LINUX_USB_QUIRKS_H */