From patchwork Thu Apr 8 13:16:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 12191045 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 EE7D3C433ED for ; Thu, 8 Apr 2021 13:16:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B60316113A for ; Thu, 8 Apr 2021 13:16:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231620AbhDHNQ3 (ORCPT ); Thu, 8 Apr 2021 09:16:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:36534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229741AbhDHNQ1 (ORCPT ); Thu, 8 Apr 2021 09:16:27 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ABB46610A6; Thu, 8 Apr 2021 13:16:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617887776; bh=Ke8qJp63FlrDKDKHCYuGMZj07d+yIBbFrD3Dth06hL0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jHwfFrlkbHn+WMgp14S6HZHTsLHGmFqkiPf+9c6SGy+kbBYPRSnuIxOxpntjuYlfU t//gO9AFUei9CCI80rz74Rvek5iBOiIY1FP10SYQ3+vcvX4FQf21KA9f5tK9KlR/2U KWH1eafGWbknFjGabCfz8txGxGIAurd/eessMyzmk8fLo0W0p23EQl9rKP+NX2rr/3 ph/ltF07dICiu/4H9dew44o6BgjWbi92z7fYlRNyvCrcm+BshUmGC82P8m1QfGVDp3 MMU8P1Zq5dHxcNilwe02d0egrLb0RdO1/1UerEuafB/XkTIbnHECKdZUnUTpG3vdWw SsbVQHGIVaMQg== Received: from johan by xi.lan with local (Exim 4.93.0.4) (envelope-from ) id 1lUUW4-0007Hm-KH; Thu, 08 Apr 2021 15:16:12 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: Oliver Neukum , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH v2 3/3] USB: cdc-acm: fix TIOCGSERIAL implementation Date: Thu, 8 Apr 2021 15:16:02 +0200 Message-Id: <20210408131602.27956-4-johan@kernel.org> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210408131602.27956-1-johan@kernel.org> References: <20210408131602.27956-1-johan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org TIOCSSERIAL is a horrid, underspecified, legacy interface which for most serial devices is only useful for setting the close_delay and closing_wait parameters. The xmit_fifo_size parameter could be used to set the hardware transmit fifo size of a legacy UART when it could not be detected, but the interface is limited to eight bits and should be left unset when it is not used. Similarly, baud_base could be used to set the UART base clock when it could not be detected, but might as well be left unset when it is not known (which is the case for CDC). Fix the cdc-acm TIOCGSERIAL implementation by dropping its custom interpretation of the unused xmit_fifo_size and baud_base fields, which overflowed the former with the URB buffer size and set the latter to the current line speed. Also return the port line number, which is the only other value used besides the close parameters. Note that the current line speed can still be retrieved through the standard termios interfaces. Fixes: 18c75720e667 ("USB: allow users to run setserial with cdc-acm") Signed-off-by: Johan Hovold Acked-by: Oliver Neukum --- drivers/usb/class/cdc-acm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 43e31dad4831..b74713518b3a 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -929,8 +929,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct acm *acm = tty->driver_data; - ss->xmit_fifo_size = acm->writesize; - ss->baud_base = le32_to_cpu(acm->line.dwDTERate); + ss->line = acm->minor; ss->close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE :