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=1794064880; b=Gd9FpScDTpsLpt6QWj285GPwEkcXb23WJgJ3UICYSiAtuOBsqMynFMEZYc0gJKkEx++j GZ2ddiZD3ciSnyxnRxuRxEezIgMy87mOdb289EkN8AdYe+tEzXBewO90ozLcFpoK73dlx AEHOchSDyDjdV+LEkt+xF95vAmzDK4Q6jU6qG3bBo+ACz4V7OOHEPz43OD3NWtP19CJPY Yyc1pA18+wQXJPkGODq5Xftstar3oEd5mtbgAfp9drjKmklLdA15v0aYqnW9XD6j1Pzqd SIW8YJoI7XrJ+AsCh+aYwzNdVEpJXSEpbCCxketDI1DHzDXLY2ufIOm/ygxUBLVV27Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794064880; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=63M5mS+jJrOedN/JHiFnZB7KnQ/cdYIYjLvRD6KLEn8=; b=ib06z8PjRi6qZb3JB58TgfCQsS+DiApsoygf1rKLdW3oEQZUea7jwoe9lVLd7FGJTGd/ JPbHNoSI+uHserBZ6NMMOCpF5dgpsD/6jh2fJWPbM297A3MJ8w/xVRIi4sfUQGUdEDQPD 3ug8bSNhlR627U0Bx7lYJ0lx2/LMGGOrGqjRGWAXyqohjCnF6M7A8v3zBKefkLUg0d0+2 aqnvojYqdSuICLKbYiXANOIBR+MgZfTULrwhVHd/Lmx8RWxuUl9qYub8EPIpXlN2qILEk ROXhxH0ikCC2ATebNbzgjgl/qMmiAxo/OjUKbLzNRnSz23OMelo6MRiekmPAMAMXixg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eGnkSCrX; 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 DEAD7606CE59; Sat, 7 Nov 2026 15:21:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eGnkSCrX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CDC51F0089F; Sat, 7 Nov 2026 15:21:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794064879; bh=63M5mS+jJrOedN/JHiFnZB7KnQ/cdYIYjLvRD6KLEn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eGnkSCrXqjqPsaTQRNWSxlRLzlRJzEG3HLVrZXiI9KLSiCu5zhgfyLLzjBohpIB1/ b0yI/cidQuD/kYxcVC7u1i0grn2qZZh2FumoaI86P9CNY1URMmXNgooUfYs2cI7Nw1 jBtVolZ0FbTVZg4AYZCkzm1HbEz3+mLq3AdUHySw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicolai Buchwitz , Sasha Levin Subject: [PATCH 7.3 0755/1257] serial: amba-pl011: honour delay_rts_before_send for every write Date: Sat, 7 Nov 2026 08:50:51 -0500 Message-ID: <20261107135000.140628715@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolai Buchwitz [ Upstream commit 8a9750209596be35d109de5aa89623b049855c67 ] While the driver waits out delay_rts_before_send, another write calls pl011_start_tx() again. pl011_rs485_tx_start() then switches straight to SEND, and the data goes out before the delay has passed. Leave the start to the trigger_start_tx timer while it is pending. Fixes: 2c1fd53af21b ("serial: amba-pl011: Fix RTS handling in RS485 mode") Cc: stable@vger.kernel.org Signed-off-by: Nicolai Buchwitz Link: https://patch.msgid.link/20261011-fix-pl011-rs485-rts-delay-v1-1-5078e61bc408@tipi-net.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/amba-pl011.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index e67f2ac454b63..d57b39f58a9bf 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1420,10 +1420,6 @@ static void pl011_rs485_tx_start(struct uart_amba_port *uap) struct uart_port *port = &uap->port; u32 cr; - if (uap->rs485_tx_state == WAIT_AFTER_RTS) { - uap->rs485_tx_state = SEND; - return; - } if (uap->rs485_tx_state == WAIT_AFTER_SEND || uap->rs485_tx_state == WAIT_AFTER_SEND_DELAY) { hrtimer_try_to_cancel(&uap->trigger_stop_tx); @@ -1462,6 +1458,10 @@ static void pl011_start_tx(struct uart_port *port) if ((uap->port.rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_state != SEND) { + /* trigger_start_tx starts TX once delay_rts_before_send passed */ + if (uap->rs485_tx_state == WAIT_AFTER_RTS) + return; + pl011_rs485_tx_start(uap); if (uap->rs485_tx_state == WAIT_AFTER_RTS) return; @@ -1478,8 +1478,10 @@ static enum hrtimer_restart pl011_trigger_start_tx(struct hrtimer *t) unsigned long flags; uart_port_lock_irqsave(&uap->port, &flags); - if (uap->rs485_tx_state == WAIT_AFTER_RTS) + if (uap->rs485_tx_state == WAIT_AFTER_RTS) { + uap->rs485_tx_state = SEND; pl011_start_tx(&uap->port); + } uart_port_unlock_irqrestore(&uap->port, flags); return HRTIMER_NORESTART; -- 2.53.0