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 C65EBECAAA1 for ; Tue, 6 Sep 2022 13:56:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238835AbiIFN4z (ORCPT ); Tue, 6 Sep 2022 09:56:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240026AbiIFNyW (ORCPT ); Tue, 6 Sep 2022 09:54:22 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C4C180E9A; Tue, 6 Sep 2022 06:41:19 -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 B497BB816A0; Tue, 6 Sep 2022 13:41:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24AE2C433B5; Tue, 6 Sep 2022 13:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471671; bh=m9DIWf9ufwNNTQBYkogqjdGKTwxaeyTIk20g2hFR/Us=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hFMoz5/OHJD1cFrt0CzMoTxsx2H7LGY4EzY3R763ByGnOTiNYYTO169bSnOxNsSiV /bdo1VxtcF+JD3hT+tadyYUPQg4wsb0waaANZBwk0SJM3cm+c5DDgKfEjhxoq/GSkE ZW8WvIBybFC8+PZbmXy/v9qrKZJXFfeSqzsTmwoE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jonathan Woithe , Johan Hovold Subject: [PATCH 5.15 107/107] USB: serial: ch341: fix disabled rx timer on older devices Date: Tue, 6 Sep 2022 15:31:28 +0200 Message-Id: <20220906132826.402470325@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132821.713989422@linuxfoundation.org> References: <20220906132821.713989422@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ch341.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -259,8 +259,12 @@ static int ch341_set_baudrate_lcr(struct /* * 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. */ - val |= BIT(7); + if (priv->version > 0x27) + val |= BIT(7); r = ch341_control_out(dev, CH341_REQ_WRITE_REG, CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER,