From patchwork Fri Sep 13 08:39:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Esben Haabendal X-Patchwork-Id: 828943 Received: from www530.your-server.de (www530.your-server.de [188.40.30.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F6171BDA95; Fri, 13 Sep 2024 08:40:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=188.40.30.78 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726216803; cv=none; b=nveyDAXMMcuCOOfe3gF6f5OaN8n8iOnFaJExmw7u3Ts12yQHRVTm9Yu67x08m5JjN2evoJqxOzv08PW0wQKbYXUOyvTQNH8kVEzjJNdXM5ps1bh/DtYbFQg1bi+fQOwRbZUMTxH0wnsL3XMicl/8aFFSvNSmTi3QK+TJ8xvW/KI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726216803; c=relaxed/simple; bh=a8ByUJ/uOEUjYWDnE/dtInA626JBUnf9q+ifF8JKvZE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=uKnTsxnXiawSG9wcPxaQV4ZaXczsGjgIjHZDBKt7/NhlqqTe6bLmS7+/Pvg6DC7dsQ1ZgBLRfvA6E4NO6C5GgGC2mthG2tTH5CFBG5DWqOVxtlNhlmH0f65Jh7y4YYenblwoD27woSoQuDKJrUK/specvTs9NitX1hCsWATCCUY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=geanix.com; spf=pass smtp.mailfrom=geanix.com; dkim=pass (2048-bit key) header.d=geanix.com header.i=@geanix.com header.b=FhBEH4dV; arc=none smtp.client-ip=188.40.30.78 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=geanix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=geanix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=geanix.com header.i=@geanix.com header.b="FhBEH4dV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=geanix.com; s=default2211; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID; bh=Cn4kUwYeuytQMsE365PcfJ/lfyo4K65OPmJ3B2UpHak=; b=FhBEH4dVFNOQBRMRZHZb4eqiIj LCLbWGFcapAevOvXliPBCb+AU2jQj7+2K9WHXJ5DAA01l7YWuvH8i8SnQl3YgX2JVePStIdRvKixO fZ2BwjSg42mEx3qsG1p3XLBf+vH+wGrssYzPpWlAhZ5Fz5J2bJjCSytYTYkBUauCgW9on87ukkkne eiMHRAULPYfvGHLkSdzY+aLlthac8OjrfEPSfBRVowstAWfdC+beauPbYv2C09+uB3dVWZRloHl3H niLiQIIlaJFwfZAnCWPDrIcOAmQ8CcbijjzU45OwF5zNCceifYnpNgECBlqn6eL40G8AJuq/6jQrD 2u5z5TSA==; Received: from sslproxy07.your-server.de ([78.47.199.104]) by www530.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sp1qM-000Dwt-ED; Fri, 13 Sep 2024 10:39:54 +0200 Received: from [80.62.117.18] (helo=localhost) by sslproxy07.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sp1qL-0003OG-14; Fri, 13 Sep 2024 10:39:53 +0200 From: Esben Haabendal Date: Fri, 13 Sep 2024 10:39:50 +0200 Subject: [PATCH 2/2] serial: imx: Add more comments on port lock status Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240913-serial-imx-lockfix-v1-2-4d102746c89d@geanix.com> References: <20240913-serial-imx-lockfix-v1-0-4d102746c89d@geanix.com> In-Reply-To: <20240913-serial-imx-lockfix-v1-0-4d102746c89d@geanix.com> To: Greg Kroah-Hartman , Jiri Slaby , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , John Ogness Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Esben Haabendal X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1726216791; l=2785; i=esben@geanix.com; s=20240523; h=from:subject:message-id; bh=a8ByUJ/uOEUjYWDnE/dtInA626JBUnf9q+ifF8JKvZE=; b=AMZZDzPDMOyiJ4EEnRXHPd4iG2IDMAY8tt+eJX/ZtFaPyLYNpgZWBCltOds8cFxRIf07u6wm5 QSYxm2nthw7BKVpn2JUzUKnjm2szURFzUudeE3uSAnPiQMB16eDMI4f X-Developer-Key: i=esben@geanix.com; a=ed25519; pk=PbXoezm+CERhtgVeF/QAgXtEzSkDIahcWfC7RIXNdEk= X-Authenticated-Sender: esben@geanix.com X-Virus-Scanned: Clear (ClamAV 0.103.10/27396/Thu Sep 12 10:46:40 2024) Comments regarding status of port.lock on internal functions is useful when reviewing correct handling of registers that must be protected by this lock. Signed-off-by: Esben Haabendal --- drivers/tty/serial/imx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index efa3eb3a2c57..bea4510743ef 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -370,6 +370,7 @@ static void imx_uart_soft_reset(struct imx_port *sport) sport->idle_counter = 0; } +/* called with port.lock taken and irqs off */ static void imx_uart_disable_loopback_rs485(struct imx_port *sport) { unsigned int uts; @@ -470,6 +471,7 @@ static void imx_uart_stop_tx(struct uart_port *port) } } +/* called with port.lock taken and irqs off */ static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback) { struct imx_port *sport = to_imx_port(port); @@ -803,6 +805,8 @@ static irqreturn_t imx_uart_txint(int irq, void *dev_id) * issuing soft reset to the UART (just stop/start of RX does not help). Note * that what we do here is sending isolated start bit about 2.4 times shorter * than it is to be on UART configured baud rate. + * + * Called with port.lock taken and irqs off. */ static void imx_uart_check_flood(struct imx_port *sport, u32 usr2) { @@ -838,6 +842,7 @@ static void imx_uart_check_flood(struct imx_port *sport, u32 usr2) } } +/* called with port.lock taken and irqs off */ static irqreturn_t __imx_uart_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; @@ -916,6 +921,7 @@ static void imx_uart_clear_rx_errors(struct imx_port *sport); /* * We have a modem side uart, so the meanings of RTS and CTS are inverted. */ +/* called with port.lock taken and irqs off */ static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) { unsigned int tmp = TIOCM_DSR; @@ -938,6 +944,8 @@ static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) /* * Handle any change of modem status signal since we were last called. + * + * Called with port.lock taken and irqs off. */ static void imx_uart_mctrl_check(struct imx_port *sport) { @@ -1277,6 +1285,7 @@ static int imx_uart_start_rx_dma(struct imx_port *sport) return 0; } +/* called with port.lock taken and irqs off */ static void imx_uart_clear_rx_errors(struct imx_port *sport) { struct tty_port *port = &sport->port.state->port; @@ -1407,6 +1416,7 @@ static int imx_uart_dma_init(struct imx_port *sport) return ret; } +/* called with port.lock taken and irqs off */ static void imx_uart_enable_dma(struct imx_port *sport) { u32 ucr1;