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 55997C433E2 for ; Fri, 29 May 2020 07:41:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 365CF2074D for ; Fri, 29 May 2020 07:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590738106; bh=owQZ44lljtusplVpm8qJlWg5ULwsNfw+yCykx40B8kE=; h=Subject:To:From:Date:List-ID:From; b=cRb7cDxbLq8MsEWSht2yHs6bDjMZ8jPhMlvN7n5wLc49VhYTgueSf9Q7z7+0uZfN2 Ijszvt41Rwwan5rqMfti0ojQXsCevRDW8XWfgpI6eqzA9NWSANmmyZOykNlwZQODfo E/da/A+eKwWbEw4mFOnaCJiElUwGI1juG5Ju06UM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726701AbgE2Hlo (ORCPT ); Fri, 29 May 2020 03:41:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:52656 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727000AbgE2Hln (ORCPT ); Fri, 29 May 2020 03:41:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 A464E208A7; Fri, 29 May 2020 07:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590738103; bh=owQZ44lljtusplVpm8qJlWg5ULwsNfw+yCykx40B8kE=; h=Subject:To:From:Date:From; b=Z8cJfaNe1Tf6NXFMeTFTL0V/OFWneh18qcaRdJtjYFsFtnWiiYoUiY4praC8LvJhe V+hxRZ0/RF7UmwkqHWImDm8bYtO5SQk9ozng0knlw2Q+LOt9XrwDk+DC6HViHj9tq4 xdH87uOFgW7oUYFZquD8YZ7eIv2GFagY2k8dQ2Oo= Subject: patch "USB: serial: ch341: add basis for quirk detection" added to usb-testing To: public@hansmi.ch, johan@kernel.org, stable@vger.kernel.org From: Date: Fri, 29 May 2020 09:41:28 +0200 Message-ID: <1590738088239131@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 USB: serial: ch341: add basis for quirk detection 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-testing 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 be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From c404bf4aa9236cb4d1068e499ae42acf48a6ff97 Mon Sep 17 00:00:00 2001 From: Michael Hanselmann Date: Tue, 31 Mar 2020 23:37:18 +0000 Subject: USB: serial: ch341: add basis for quirk detection A subset of CH341 devices does not support all features, namely the prescaler is limited to a reduced precision and there is no support for sending a RS232 break condition. This patch adds a detection function which will be extended to set quirk flags as they're implemented. The author's affected device has an imprint of "340" on the turquoise-colored plug, but not all such devices appear to be affected. Signed-off-by: Michael Hanselmann Link: https://lore.kernel.org/r/1e1ae0da6082bb528a44ef323d4e1d3733d38858.1585697281.git.public@hansmi.ch [ johan: use long type for quirks; rephrase and use port device for messages; handle short reads; set quirk flags directly in helper function ] Cc: stable # 5.5 Signed-off-by: Johan Hovold --- drivers/usb/serial/ch341.c | 53 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index c5ecdcd51ffc..f2b93f4554a7 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -87,6 +87,7 @@ struct ch341_private { u8 mcr; u8 msr; u8 lcr; + unsigned long quirks; }; static void ch341_set_termios(struct tty_struct *tty, @@ -308,6 +309,53 @@ out: kfree(buffer); return r; } +static int ch341_detect_quirks(struct usb_serial_port *port) +{ + struct ch341_private *priv = usb_get_serial_port_data(port); + struct usb_device *udev = port->serial->dev; + const unsigned int size = 2; + unsigned long quirks = 0; + char *buffer; + int r; + + buffer = kmalloc(size, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + /* + * A subset of CH34x devices does not support all features. The + * prescaler is limited and there is no support for sending a RS232 + * break condition. A read failure when trying to set up the latter is + * used to detect these devices. + */ + r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, + CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); + if (r == -EPIPE) { + dev_dbg(&port->dev, "break control not supported\n"); + r = 0; + goto out; + } + + if (r != size) { + if (r >= 0) + r = -EIO; + dev_err(&port->dev, "failed to read break control: %d\n", r); + goto out; + } + + r = 0; +out: + kfree(buffer); + + if (quirks) { + dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); + priv->quirks |= quirks; + } + + return r; +} + static int ch341_port_probe(struct usb_serial_port *port) { struct ch341_private *priv; @@ -330,6 +378,11 @@ static int ch341_port_probe(struct usb_serial_port *port) goto error; usb_set_serial_port_data(port, priv); + + r = ch341_detect_quirks(port); + if (r < 0) + goto error; + return 0; error: kfree(priv); -- 2.26.2