From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Jiri Slaby <jslaby@suse.com>, Chen Wandun <chenwandun@huawei.com>,
gregkh@linuxfoundation.org, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org, beomho.seo@samsung.com,
sw0312.kim@samsung.com, youngmin.nam@samsung.com
Subject: Re: [PATCH v2] tty: serial: samsung: remove variable 'ufstat' set but not used
Date: Fri, 22 Nov 2019 15:13:59 +0100 [thread overview]
Message-ID: <4a5c6729-30f3-bcf1-9092-1ea810324f92@samsung.com> (raw)
In-Reply-To: <d7a42300-6c67-70c4-4c90-5f05c65c421c@suse.com>
Hi Jiri,
On 22.11.2019 13:08, Jiri Slaby wrote:
> On 22. 11. 19, 13:04, Chen Wandun wrote:
>> Fixes gcc '-Wunused-but-set-variable' warning:
>>
>> drivers/tty/serial/samsung_tty.c: In function s3c24xx_serial_rx_chars_dma:
>> drivers/tty/serial/samsung_tty.c:549:24: warning: variable ufstat set but not used [-Wunused-but-set-variable]
>>
>> Signed-off-by: Chen Wandun <chenwandun@huawei.com>
>> ---
>> drivers/tty/serial/samsung_tty.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
>> index 83fd516..ab3c7d1 100644
>> --- a/drivers/tty/serial/samsung_tty.c
>> +++ b/drivers/tty/serial/samsung_tty.c
>> @@ -546,7 +546,7 @@ 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;
>> + unsigned int utrstat, received;
>> struct s3c24xx_uart_port *ourport = dev_id;
>> struct uart_port *port = &ourport->port;
>> struct s3c24xx_uart_dma *dma = ourport->dma;
>> @@ -556,7 +556,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
>> struct dma_tx_state state;
>>
>> utrstat = rd_regl(port, S3C2410_UTRSTAT);
>> - ufstat = rd_regl(port, S3C2410_UFSTAT);
>> + rd_regl(port, S3C2410_UFSTAT);
> The question (CCed some samsung people) is whether we have to spend the
> cycles reading the register at all? Does it have side-effects?
Reading this register doesn't have any side effects, so it is safe to
remove rd_regl(port, S3C2410_UFSTAT) at all in this function. Tested on
Exynos5422-based OdroidXU3 board.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
prev parent reply other threads:[~2019-11-22 14:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 11:12 [PATCH] {tty: serial, nand: onenand}: remove variable 'ufstat' set but not used Chen Wandun
2019-11-22 11:14 ` Greg KH
2019-11-22 11:33 ` Chen Wandun
2019-11-22 11:38 ` Greg KH
2019-11-22 12:04 ` [PATCH v2] tty: serial: samsung: " Chen Wandun
2019-11-22 12:08 ` Jiri Slaby
2019-11-22 14:13 ` Marek Szyprowski [this message]
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