From patchwork Tue Jul 12 11:53:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 590030 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 3371EC43334 for ; Tue, 12 Jul 2022 11:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232753AbiGLLyd (ORCPT ); Tue, 12 Jul 2022 07:54:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232760AbiGLLyP (ORCPT ); Tue, 12 Jul 2022 07:54:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB6D1B38D6 for ; Tue, 12 Jul 2022 04:53:21 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 889CD614D2 for ; Tue, 12 Jul 2022 11:53:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5E99C341CA; Tue, 12 Jul 2022 11:53:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657626800; bh=R1PUUU3HotDygkPBJux3mO3BxfC2b5NYP/yyWUr7vs8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LdNHfUhULpt3w/p5wPmhy7N/mATybEKjyFMgIJjo1WjU4wvkzNaECbiRyeWhPAHsD +/bQOhJX1505GkUjwGfEHr2QwrL597NJMFmTjYcVbv3pxFRY2I5we3SmYpbGWIcyq1 uRQMvB/5nArdvaKOlcacWyt8xNQcBsMVPxxXAtCkniYIiqrU25LQcacbREou9AGdUP iRtKqJ9XP5g7vEYaplmFYAJVNMYG5rbQa1i3kt/vVx/sJG92XFi5ThS0nXSUl+vIfN w4oZKx2JKzfLzfILFD5om7ca6TD1Q8v6J/vB575VU0optz3HoYHzrCj0zM7T+Iv2Qr aVCLyLnqXHjPg== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: linux-usb@vger.kernel.org Cc: =?utf-8?q?Pali_Roh=C3=A1r?= , Johan Hovold , Greg Kroah-Hartman , =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH v2 6/7] USB: serial: ftdi_sio: Fix custom_divisor and c_*speed for ASYNC_SPD_CUST Date: Tue, 12 Jul 2022 13:53:05 +0200 Message-Id: <20220712115306.26471-7-kabel@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220712115306.26471-1-kabel@kernel.org> References: <20220712115306.26471-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Pali Rohár When ASYNC_SPD_CUST is used, update custom_divisor and c_*speed fields so that they correspond to the newly set baud rate value, so that userspace GET ioctls will see the true baud rate that is being used. Signed-off-by: Pali Rohár Tested-by: Marek Behún Signed-off-by: Marek Behún --- drivers/usb/serial/ftdi_sio.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 5db1293bb7a2..39e8c5d06157 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1303,6 +1303,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty, { struct ftdi_private *priv = usb_get_serial_port_data(port); struct device *dev = &port->dev; + int fix_custom_divisor = 0; int div_value = 0; int div_okay = 1; int baud; @@ -1317,6 +1318,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty, if (baud == 38400 && ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) && (priv->custom_divisor)) { + fix_custom_divisor = 1; baud = DIV_ROUND_CLOSEST(priv->baud_base, priv->custom_divisor); dev_dbg(dev, "%s - custom divisor %d sets baud rate to %d\n", __func__, priv->custom_divisor, baud); @@ -1401,7 +1403,19 @@ static u32 get_ftdi_divisor(struct tty_struct *tty, ftdi_chip_name[priv->chip_type]); } + /* Fix deprecated async-compatible custom_divisor hack and update tty baud rate */ + if (fix_custom_divisor) { + priv->custom_divisor = DIV_ROUND_CLOSEST(priv->baud_base, baud); + old_baud = baud; + baud = 38400; + } + tty_encode_baud_rate(tty, baud, baud); + + /* For async-compatible custom_divisor store into TCGETS2 c_*speed fields real baud rate */ + if (fix_custom_divisor) + tty->termios.c_ispeed = tty->termios.c_ospeed = old_baud; + return div_value; } @@ -2674,6 +2688,8 @@ static void ftdi_set_termios(struct tty_struct *tty, dev_dbg(ddev, "%s: forcing baud rate for this device\n", __func__); tty_encode_baud_rate(tty, priv->force_baud, priv->force_baud); + termios->c_ispeed = termios->c_ospeed = + DIV_ROUND_CLOSEST(priv->baud_base, priv->custom_divisor); } /* Force RTS-CTS if this device requires it. */