From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751458AbbIKGIB (ORCPT ); Fri, 11 Sep 2015 02:08:01 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:11519 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751036AbbIKGH7 (ORCPT ); Fri, 11 Sep 2015 02:07:59 -0400 X-AuditID: cbfec7f4-f79c56d0000012ee-ad-55f26fbc3ef5 Subject: Re: [PATCH v2 4/4] serial: samsung: Fix UART status handling in DMA mode To: Robert Baldyga , gregkh@linuxfoundation.org References: <1441892476-14273-1-git-send-email-r.baldyga@samsung.com> <1441892476-14273-5-git-send-email-r.baldyga@samsung.com> Cc: jslaby@suse.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, m.szyprowski@samsung.com From: Krzysztof Kozlowski X-Enigmail-Draft-Status: N1110 Message-id: <55F26FBE.3060500@samsung.com> Date: Fri, 11 Sep 2015 15:07:58 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-version: 1.0 In-reply-to: <1441892476-14273-5-git-send-email-r.baldyga@samsung.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrPLMWRmVeSWpSXmKPExsVy+t/xq7p78j+FGiyewmnRvHg9m8WUDR+Y LF6/MLS4vGsOm8WZxb3sFmuP3GW3eHB4J7sDu8f+uWvYPfq2rGL0WL/lKovH501yASxRXDYp qTmZZalF+nYJXBk9Zz+yF9wVq/j8ZilbA+M+oS5GTg4JAROJ29tOMUHYYhIX7q1n62Lk4hAS WMoocWD2BVYI5wujxI+Z29i7GDk4hAWCJb6vTQZpEBFwk1j07y4biC0k0Mgo8e2jNojNLJAt 8bF5GQuIzSZgLLF5+RI2iAVyEr3dk8DivAJaEmvO7wCzWQRUJZ5f72YHsUUFIiROnX3LBlEj KPFj8j2wGk6gXa1N7WAnMAvoSdy/qAWxSl5i85q3zBMYBWch6ZiFUDULSdUCRuZVjKKppckF xUnpuYZ6xYm5xaV56XrJ+bmbGCHB/mUH4+JjVocYBTgYlXh4LVQ/hQqxJpYVV+YeYpTgYFYS 4TWQAwrxpiRWVqUW5ccXleakFh9ilOZgURLnnbvrfYiQQHpiSWp2ampBahFMlomDU6qBcdY2 hi9njDfpcdrmxhkUJKlfu306NS9xkv4pP7c5faUb97WetBHm/pt6PvQ657mU+6fSKxXnTObd F122IaBujaHJzfIFTHd6ZA2Duj8Jnis2SvU/5nnR2zHSJ/PJrYMnnL78DbuTbl1gULCAcdft 6FNyOa/75dizJ/fsypvRKbjfz2xO3uloJZbijERDLeai4kQAXdb06HICAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10.09.2015 22:41, Robert Baldyga wrote: > This patch fixes UART status handling in DMA mode. I don't see any changes here. You did not respond to my comment neither. Code looks itself good... except a locking issue but I don't know what's the cause. It may be not related to the patchset and maybe just not all of issues are fixed yet. Anyway I'll describe it in 3/4. Best regards, Krzysztof > For this purpose we > use s3c24xx_serial_rx_drain_fifo() instead of uart_rx_drain_fifo(), which > does the same thing plus checks for special conditions (such as 'break'). > > Thanks to this we have, for example, Magic SysRq handling, which was > missing in DMA mode so far. Since we can use UART in DMA mode as serial > console, this is a quite important improvement. > > This change additionally simplifies RX handling code, as we no longer > need uart_rx_drain_fifo() function, so we can remove it. > > Reported-by: Marek Szyprowski > Signed-off-by: Robert Baldyga > --- > drivers/tty/serial/samsung.c | 30 +++--------------------------- > 1 file changed, 3 insertions(+), 27 deletions(-) > > diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c > index 1d7dd86..d72cd73 100644 > --- a/drivers/tty/serial/samsung.c > +++ b/drivers/tty/serial/samsung.c > @@ -385,32 +385,6 @@ static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport, > } > } > > -static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport, > - unsigned long ufstat); > - > -static void uart_rx_drain_fifo(struct s3c24xx_uart_port *ourport) > -{ > - struct uart_port *port = &ourport->port; > - struct tty_port *tty = &port->state->port; > - unsigned int ch, ufstat; > - unsigned int count; > - > - ufstat = rd_regl(port, S3C2410_UFSTAT); > - count = s3c24xx_serial_rx_fifocnt(ourport, ufstat); > - > - if (!count) > - return; > - > - while (count-- > 0) { > - ch = rd_regb(port, S3C2410_URXH); > - > - ourport->port.icount.rx++; > - tty_insert_flip_char(tty, ch, TTY_NORMAL); > - } > - > - tty_flip_buffer_push(tty); > -} > - > static void s3c24xx_serial_stop_rx(struct uart_port *port) > { > struct s3c24xx_uart_port *ourport = to_ourport(port); > @@ -573,6 +547,8 @@ static void enable_rx_pio(struct s3c24xx_uart_port *ourport) > ourport->rx_mode = S3C24XX_RX_PIO; > } > > +static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport); > + > static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id) > { > unsigned int utrstat, ufstat, received; > @@ -606,7 +582,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id) > enable_rx_pio(ourport); > } > > - uart_rx_drain_fifo(ourport); > + s3c24xx_serial_rx_drain_fifo(ourport); > > if (tty) { > tty_flip_buffer_push(t); >