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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81488ECAAA1 for ; Tue, 6 Sep 2022 13:38:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233459AbiIFNiZ (ORCPT ); Tue, 6 Sep 2022 09:38:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240795AbiIFNhs (ORCPT ); Tue, 6 Sep 2022 09:37:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5E801BE91; Tue, 6 Sep 2022 06:34:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2DA70B81637; Tue, 6 Sep 2022 13:34:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC593C433D7; Tue, 6 Sep 2022 13:34:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662471274; bh=rC17ttJnc2CYDwxXtKcfCFiIib9n7dshKSLsLvNzlXA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EnlYfVZikJAhCS9qCMnONQfyFJgKt29NRRhTzQ9AflAKp4rWGiejVj5It4Mvg0+Iu NDWLAzqtJlebRl1MJUg+5sUlJuRMJd6ZK9I8wIpJ/7IbZP2LNi9dTWfi5+0C8WLzBE G3s95clYlZQ7oNerGg+guqNi+iE6rYR8s9c+YCMoWFEqsuW6dsjnwftw9krCOfAwNG IeCMgAyCtFdgtT4Jz+jEINKDm857YMV7KffvUOznAylLfUQXhoEHMdCVoBmLJr3HuJ KHuYh1XCe+zYez4EkuaObEOemOKFw2KpPzaC04UlhvwI3Fey1r7b0Jr2VIk8oJ9YkJ di3x2PpOs/4xA== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oVYit-0006t1-Ay; Tue, 06 Sep 2022 15:34:39 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , Jonathan Woithe Subject: [PATCH stable-5.4 3/3] USB: serial: ch341: fix disabled rx timer on older devices Date: Tue, 6 Sep 2022 15:34:35 +0200 Message-Id: <20220906133435.26452-4-johan@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220906133435.26452-1-johan@kernel.org> References: <20220906133435.26452-1-johan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 41ca302a697b64a3dab4676e01d0d11bb184737d upstream. At least one older CH341 appears to have the RX timer enable bit inverted so that setting it disables the RX timer and prevents the FIFO from emptying until it is full. Only set the RX timer enable bit for devices with version newer than 0x27 (even though this probably affects all pre-0x30 devices). Reported-by: Jonathan Woithe Tested-by: Jonathan Woithe Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au Fixes: 4e46c410e050 ("USB: serial: ch341: reinitialize chip on reconfiguration") Cc: stable@vger.kernel.org # 4.10 Signed-off-by: Johan Hovold [ johan: backport to 5.4 ] Signed-off-by: Johan Hovold --- drivers/usb/serial/ch341.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index be44d6c28df6..f37bde88eb5d 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -177,8 +177,12 @@ static int ch341_set_baudrate_lcr(struct usb_device *dev, /* * CH341A buffers data until a full endpoint-size packet (32 bytes) * has been received unless bit 7 is set. + * + * At least one device with version 0x27 appears to have this bit + * inverted. */ - a |= BIT(7); + if (priv->version > 0x27) + a |= BIT(7); r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a); if (r) -- 2.35.1