From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792639092; b=vAtWcT4rjzwz4y5lsOCu5HQLA9x9UBUczFMrGRPRHD4ZqiUMhVjxtnddHIErWhZFrABR hm+WGV4wYIBDtXBFK/Pajz+C6dtMdZSFdcR4U7CbvXJOmGpSTLc8+cp8VHV0IJ6/hXAbH BeSahVNhCUJrDjk9UJd3epo0uGFi0fj5gRDkmuxlfDrdG7F9NSzir/79h8buaNgShkXHt tb3NkCvFgjIwx6Je09u6c04RvRyAOSZDZuVb91rxrDLl5GQtUePPVGKND4vJAadDxCddo ST6AhVBNkWzEOucKh4MP70plw/YbE/avWu+HorXUZLi0Z11X0eiOU2VT9vm4ZDeBNpw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792639092; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=oZVXMNVOkciS58mAG+Cj8NUgdg2hhDicWtuF2JjUrAg=; b=iRJQBymIhQlU11Dspq6WMBHOkKOA/U3QGoEQV/TqPKnoQaUHuJNfyAiNIsadVYw9b4d6 9+8RMOwAmYLlNLu2U5f8284747QO+LDxWIr4MOTN0Tag23yBsrjRetp/ZooYRnYdUQb/3 XIELoXzvwjsI39WIcFUD3JH9HPn6CgU0piBBRV8gk/QBpqQzXXhI9S4VTgocAIvMor6Hq 4ddjlurlFJGGuqdATrvq/5BgyraVmZYHS4Z2t2kRsjkTzlffUlhueFjEt+OIvsZNAAYL9 9LiW9nQDFl5zrKtX4TgBZE0r/+HINqjyHqFq0yg/XsRVls9Q+7bTWRFYnKCeiM3HKXw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MIfhaUL9; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 765EB60A260C for ; Thu, 22 Oct 2026 03:18:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MIfhaUL9 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDA981F000C1; Thu, 22 Oct 2026 03:18:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792639092; bh=oZVXMNVOkciS58mAG+Cj8NUgdg2hhDicWtuF2JjUrAg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MIfhaUL9whkB3isK/tQP5ankKNk8NQsNE3Zfo+F6LXcfD0ifNzh9prpIQjrtSgarV 0eBoeWPE9zUyBR2XhVjdKhp6y+7QUe0fJZ6WNeyzPnYgvzbzo1wQvSiz7nkmXBUnC+ VBxdbk/CMpQvI//G5FnIqKz2YScyJ17/sSVYDXb3/gSpnWU0QwB+8N2iEBQRlcU1rI UCMQhCGuRzyzg4/gNaw5UCYMB0xFdZWhCx1yaYfGCvsQne8St25M3lpOTHGiuCjQHj SAsTocKx3zf9iSNex4IV191vQSsjb3GQZ32D5DjLanLCMa9XM499VeHqq9Gnh3F1Ks g32uYiwoMQyMw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 1/2] tty: serial: lpuart: deassert RTS while reconfiguring in set_termios() Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?U2hlcnJ5IFN1biAoT1NTKQ==?= Cc: linux-serial@vger.kernel.org In-Reply-To: <20261022-b4-lpuart_rts_fix-v1-1-207f91580dee@nxp.com> References: <20261022-b4-lpuart_rts_fix-v1-0-207f91580dee@nxp.com> <20261022-b4-lpuart_rts_fix-v1-1-207f91580dee@nxp.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 22 Oct 2026 03:18:11 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Sherry Sun >=20 > Commit e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of > overwriting the whole UARTMODIR register") replaced the write of 0 to > UARTMODIR before waiting for the transmission complete flag with a > write that only masks TXCTSE. As a side effect RXRTSE is no longer > cleared there, and when CRTSCTS is requested that write even sets it > while the receiver is still enabled. >=20 > RTS therefore keeps following the receiver FIFO level during the whole > reconfiguration, so the remote side may keep sending, or start sending, > right before set_termios() disables the receiver and reprograms the > baud rate. The characters in flight are then lost or corrupted, and a > short RTS pulse can be observed on the line. >=20 > Mask RXRTSE in that first write as well, so that RTS is deasserted and > the remote side is asked to stop sending before the receiver is > disabled. The final write of the modem value restores both RXRTSE and > TXCTSE as requested by termios, and the other UARTMODIR fields are still > preserved. >=20 > Fixes: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of ov= erwriting the whole UARTMODIR register") > Cc: stable@vger.kernel.org > Signed-off-by: Sherry Sun Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261022-b4-lpuart_= rts_fix-v1-0-207f91580dee@nxp.com?part=3D1