From patchwork Fri Dec 27 22:45:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 854158 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 60C55155CB3; Fri, 27 Dec 2024 22:45:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735339534; cv=none; b=u9WfkBHf2VxDtrzXUkQv69trjz0gcyXnW0DIzYPl7gy646j/4wS2WhhsMEnlwPxb/rTgy/LF485fckCUkDCgAmxPM2zlUuB/vVcitwHPtr20YS5pbnTS5Gnstp+jDbQHcjOy1kRfRtO9ZqNFPt+74mEzCWnVAvf8J5elzuV7hFE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735339534; c=relaxed/simple; bh=847dnAyEyJU9u4HAy5/kzMTmcQ7OLra1Lu+DFPIQlm4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=N0rbX6n6EPPy0irmSXV28lx7+LWW/p4/cRXXVhKyhyDXd52QIEpOMlNCHUaxFQhcq35v5y95cyWaGO+76rCjp21zHVn09UTCrqrQgejXDkwPfWt+icQa16cBQcwxXci55auyyKpCVheCtAuRXY5K1SFtPRxzze4TvM3h6AWghFo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=abxtdc+e; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=dddETy03; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="abxtdc+e"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dddETy03" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1735339525; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PRm5QPZ8g+hOoTns/vkCG62fDERJWECzx09fOxeCZMk=; b=abxtdc+eMP8oYVqwVJeHXRvtPnQmU1MZod0+tFOPuDfF83vdhKffvhAzTqmQN6fqZdjKek yOavVJ3l7/HxVCMEIrSDtLadM0t/c8iZuzAC1lekGKfNLhL24yKYDpI2atx4OZ8wgNGoy6 zMszJ7W6NxBYLxAX9djCohlbOgvSQ/29OsTIE9rGSZCu/3uD3RQ+WNHzDb31613kngHU4u /qaKrWHYfYg9Q1W9IYcaYdkCbiuff5TqZNBHp1YbTn1k6ESCCpEWKzzx6Wktday6o2aqjk 6gskrXzhQ5C+JtfyBU6Ni7t5HeqjDwfWef6l3t+tZWlALUV5/zoIVlnQIS2Q+A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1735339525; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PRm5QPZ8g+hOoTns/vkCG62fDERJWECzx09fOxeCZMk=; b=dddETy03MjCIrFxjUMsaYMPUU1IdZScxuXGOHH1Dq7z6pQFZ9TFZooA0DHRa+71Hxie0d3 Ggw+Uq0g1iIFg4AA== To: Greg Kroah-Hartman Cc: Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , Esben Haabendal , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Shevchenko , Arnd Bergmann , Rengarajan S , Niklas Schnelle , Serge Semin Subject: [PATCH tty-next v4 3/6] serial: 8250: Use high-level writing function for FIFO Date: Fri, 27 Dec 2024 23:51:19 +0106 Message-Id: <20241227224523.28131-4-john.ogness@linutronix.de> In-Reply-To: <20241227224523.28131-1-john.ogness@linutronix.de> References: <20241227224523.28131-1-john.ogness@linutronix.de> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Currently serial8250_console_fifo_write() directly writes into the UART_TX register rather than using the high-level function serial8250_console_putchar(). This is because serial8250_console_putchar() waits for the holding register to become empty, which would defeat the purpose of the FIFO code. Move the LSR_THRE waiting to a new function serial8250_console_wait_putchar() so that the FIFO code can use serial8250_console_putchar(). This will be particularly important for a follow-up commit, where output bytes are inspected to track newlines. This is only refactoring and has no functional change. Signed-off-by: John Ogness Reviewed-by: Andy Shevchenko Reviewed-by: Petr Mladek --- drivers/tty/serial/8250/8250_port.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index aeacf9d452e4..812f003c252d 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -3297,11 +3297,16 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults); #ifdef CONFIG_SERIAL_8250_CONSOLE static void serial8250_console_putchar(struct uart_port *port, unsigned char ch) +{ + serial_port_out(port, UART_TX, ch); +} + +static void serial8250_console_wait_putchar(struct uart_port *port, unsigned char ch) { struct uart_8250_port *up = up_to_u8250p(port); wait_for_xmitr(up, UART_LSR_THRE); - serial_port_out(port, UART_TX, ch); + serial8250_console_putchar(port, ch); } /* @@ -3351,6 +3356,7 @@ static void serial8250_console_fifo_write(struct uart_8250_port *up, { const char *end = s + count; unsigned int fifosize = up->tx_loadsz; + struct uart_port *port = &up->port; unsigned int tx_count = 0; bool cr_sent = false; unsigned int i; @@ -3361,10 +3367,10 @@ static void serial8250_console_fifo_write(struct uart_8250_port *up, for (i = 0; i < fifosize && s != end; ++i) { if (*s == '\n' && !cr_sent) { - serial_out(up, UART_TX, '\r'); + serial8250_console_putchar(port, '\r'); cr_sent = true; } else { - serial_out(up, UART_TX, *s++); + serial8250_console_putchar(port, *s++); cr_sent = false; } } @@ -3444,7 +3450,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, if (likely(use_fifo)) serial8250_console_fifo_write(up, s, count); else - uart_console_write(port, s, count, serial8250_console_putchar); + uart_console_write(port, s, count, serial8250_console_wait_putchar); /* * Finally, wait for transmitter to become empty