From patchwork Fri Sep 6 13:13:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 826224 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 59A2B1CEABC; Fri, 6 Sep 2024 13:14:59 +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=1725628499; cv=none; b=U3wblq7D5gb470Ahko7jWNWV+ze0MMq6/o8dOi+z/UNCfo8lzbcukACgDBtQy7xoVL8fl+MA9DgEi3CT3uVJMmI/5A1JnTdXS8I1v3x0ThGoVXI5ZEuBN/43/CHd3VeMpu0AgsL+cNzjOmTxcW76V6v8O72HcsaRaEqXWkW/0Hc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725628499; c=relaxed/simple; bh=GDQOGSpitpZi51yoXPlIy1fHyV3RNsflRSIpWdUHojs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SU33NqEg6ms3u5r4amLYXxiF3N6MhQxcZg4JGv4kIU54Bs661+Gs5AmF82v20R7NvNTXG+28wvUwsjBAyBxKJRIJp10z1V4siHPQ+YTwfJOLmQv7gOXsmsYTFTagnsSXnEfgcSNLQaFy4AOptyUyTc0SK6GAffIeLAsOwGYSm+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bq5Cmu35; 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="Bq5Cmu35" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4392C4CECD; Fri, 6 Sep 2024 13:14:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725628498; bh=GDQOGSpitpZi51yoXPlIy1fHyV3RNsflRSIpWdUHojs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bq5Cmu35bzqwbyQCRRWRLSgGUGnBgwr874RRvmSLZGhDBKqEaMqpnjeZe+mngvDdl UwZ322fG3ET1JUWYspzmvU90Qi7jLoKcvE02ezvogUP7Zmr8KESzcewY2sQoXbgg35 5QjSv9+ouXWZqacpXBBTz4uAPHjc2uS6HqG+/arq+Foi1LAOCFNgPkEfAuILvwlA6M f+hSiVDQiqC+Dwjth4qg3ycSILvPWjX8IXnj3XMOxhFDZIHfwr8XzHWhIchROANmZe rnnvmShP6fWzmltkwcdb7oxEhuV8Kc6NKPU9SqMGd3TUKOk2WGvF472iVKflWDmqL4 Pjan+iRqL2zqw== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1smYo3-000000006Aq-2lPx; Fri, 06 Sep 2024 15:15:19 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: Jiri Slaby , Bjorn Andersson , Konrad Dybcio , Douglas Anderson , =?utf-8?q?N=C3=ADcolas_F_=2E_R_?= =?utf-8?q?=2E_A_=2E_Prado?= , linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH v2 7/8] serial: qcom-geni: disable interrupts during console writes Date: Fri, 6 Sep 2024 15:13:35 +0200 Message-ID: <20240906131336.23625-8-johan+linaro@kernel.org> X-Mailer: git-send-email 2.44.2 In-Reply-To: <20240906131336.23625-1-johan+linaro@kernel.org> References: <20240906131336.23625-1-johan+linaro@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Disable the GENI interrupts during console writes to reduce the risk of having interrupt handlers spinning on the port lock on other cores for extended periods of time. This can, for example, reduce the total amount of time spent in the interrupt handler during boot of the x1e80100 CRD by up to a factor nine (e.g. from 274 ms to 30 ms) while the worst case processing time drops from 19 ms to 8 ms. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Reviewed-by: Douglas Anderson Tested-by: Nícolas F. R. A. Prado Signed-off-by: Johan Hovold --- drivers/tty/serial/qcom_geni_serial.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index f8f6e9466b40..f23fd0ac3cfd 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -477,6 +477,7 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, { struct uart_port *uport; struct qcom_geni_serial_port *port; + u32 m_irq_en, s_irq_en; bool locked = true; unsigned long flags; @@ -492,6 +493,11 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, else uart_port_lock_irqsave(uport, &flags); + m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN); + s_irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN); + writel(0, uport->membase + SE_GENI_M_IRQ_EN); + writel(0, uport->membase + SE_GENI_S_IRQ_EN); + if (qcom_geni_serial_main_active(uport)) { /* Wait for completion or drain FIFO */ if (!locked || port->tx_remaining == 0) @@ -504,6 +510,9 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, __qcom_geni_serial_console_write(uport, s, count); + writel(m_irq_en, uport->membase + SE_GENI_M_IRQ_EN); + writel(s_irq_en, uport->membase + SE_GENI_S_IRQ_EN); + if (locked) uart_port_unlock_irqrestore(uport, flags); }