From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4CA991B3732; Wed, 5 Jun 2024 11:54:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717588471; cv=none; b=DmUVK9HqV7wShPdEgzQqeeH+jPdgYO4+uI3WQuB1D8nhIiMcLyDer6u8RINosDxPgcAisC2znxS9TLeemOTds3U29Wz5RAGMRtXYiqPKRMEPTVXHR3MVHZYdk470oEw78m3U6bGVJ1/9SxYkieuUfV/isN97MJSg7JsptE6CwVg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717588471; c=relaxed/simple; bh=mCP1odBp/E+seo1PF1EwA6/lK01Byu8F2UblPqk/58A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bO/A2kef2vNYh26yWZ1IxX/U3CyvM7IrySmPSxIrdvZBb59GdpjD2auX+loJ8OI8bvD4SnUrcHJ0PkWovgKfmZp+Bwpwt++NufXQOf8EodbgXVjM2luXgatqYyTQYQKEgwI6Z5KDZFbEE96bhaIs7Ce30vazUNEjb4yUVc7PkSs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rPo9/HEj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rPo9/HEj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57CA7C3277B; Wed, 5 Jun 2024 11:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717588471; bh=mCP1odBp/E+seo1PF1EwA6/lK01Byu8F2UblPqk/58A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rPo9/HEj+ry7Umr7jE5I/yh7iRSPWHjHppcMFFDU001EuuE6tT54piyHEP5FtzxiZ rBf/eXOpbHR7VLzuC2DLu/st34UWCs80qoEp9hxKyOQEag2ly9bhQNPqMtPyEeYktK ul2+CTWAmzios4JCwfbrncdfsjCibpcmp+wdC4NiJjnkLXZ1s5Ljtk4GE/ikuudhHq 5StouwHMnh/oWuCKXdDvMMV6F514kxQfIMInr1Rkt2u9Vv5VmSN/QP04BGK90wfvM8 8xTZycELbCG1mgNaVUN+cCZ9q5CYaP6DHBpMXkP0t0AuE772NsGFFmgOkvMSadWWXG 85EaAutf5o6rg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Esben Haabendal , Marc Kleine-Budde , Greg Kroah-Hartman , Sasha Levin , jirislaby@kernel.org, shawnguo@kernel.org, u.kleine-koenig@pengutronix.de, ilpo.jarvinen@linux.intel.com, cniedermaier@dh-electronics.com, l.sanfilippo@kunbus.com, frank.li@vivo.com, tglx@linutronix.de, rickaran@axis.com, linux-serial@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.15 7/9] serial: imx: Introduce timeout when waiting on transmitter empty Date: Wed, 5 Jun 2024 07:54:05 -0400 Message-ID: <20240605115415.2964165-7-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240605115415.2964165-1-sashal@kernel.org> References: <20240605115415.2964165-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.160 Content-Transfer-Encoding: 8bit From: Esben Haabendal [ Upstream commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 ] By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential deadlock. In case of the timeout, there is not much we can do, so we simply ignore the transmitter state and optimistically try to continue. Signed-off-by: Esben Haabendal Acked-by: Marc Kleine-Budde Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/imx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 0587beaaea08d..b9ef426d5aae3 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -2024,7 +2025,7 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) struct imx_port *sport = imx_uart_ports[co->index]; struct imx_port_ucrs old_ucr; unsigned long flags; - unsigned int ucr1; + unsigned int ucr1, usr2; int locked = 1; if (sport->port.sysrq) @@ -2055,8 +2056,8 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) * Finally, wait for transmitter to become empty * and restore UCR1/2/3 */ - while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)); - + read_poll_timeout_atomic(imx_uart_readl, usr2, usr2 & USR2_TXDC, + 0, USEC_PER_SEC, false, sport, USR2); imx_uart_ucrs_restore(sport, &old_ucr); if (locked) -- 2.43.0