Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v2] tty: serial: samsung: remove variable 'ufstat' set but
 not used
To:     Chen Wandun <chenwandun@huawei.com>, gregkh@linuxfoundation.org,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        beomho.seo@samsung.com, sw0312.kim@samsung.com,
        youngmin.nam@samsung.com
References: <1574421159-113624-1-git-send-email-chenwandun@huawei.com>
 <1574424258-138975-1-git-send-email-chenwandun@huawei.com>
From:   Jiri Slaby <jslaby@suse.com>
Autocrypt: addr=jslaby@suse.com; prefer-encrypt=mutual; keydata=
 mQINBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j
 rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk
 rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ
 i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx
 wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx
 ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H
 cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL
 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps
 w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm
 YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABtBxKaXJpIFNsYWJ5
 IDxqc2xhYnlAc3VzZS5jb20+iQI4BBMBAgAiBQJOkujrAhsDBgsJCAcDAgYVCAIJCgsEFgID
 AQIeAQIXgAAKCRC9JbEEBrRwSc1VD/9CxnyCYkBrzTfbi/F3/tTstr3cYOuQlpmufoEjCIXx
 PNnBVzP7XWPaHIUpp5tcweG6HNmHgnaJScMHHyG83nNAoCEPihyZC2ANQjgyOcnzDOnW2Gzf
 8v34FDQqj8CgHulD5noYBrzYRAss6K42yUxUGHOFI1Ky1602OCBRtyJrMihio0gNuC1lE4YZ
 juGZEU6MYO1jKn8QwGNpNKz/oBs7YboU7bxNTgKrxX61cSJuknhB+7rHOQJSXdY02Tt31R8G
 diot+1lO/SoB47Y0Bex7WGTXe13gZvSyJkhZa5llWI/2d/s1aq5pgrpMDpTisIpmxFx2OEkb
 jM95kLOs/J8bzostEoEJGDL4u8XxoLnOEjWyT82eKkAe4j7IGQlA9QQR2hCMsBdvZ/EoqTcd
 SqZSOto9eLQkjZLz0BmeYIL8SPkgnVAJ/FEK44NrHUGzjzdkE7a0jNvHt8ztw6S+gACVpysi
 QYo2OH8hZGaajtJ8mrgN2Lxg7CpQ0F6t/N1aa/+A2FwdRw5sHBqA4PH8s0Apqu66Q94YFzzu
 8OWkSPLgTjtyZcez79EQt02u8xH8dikk7API/PYOY+462qqbahpRGaYdvloaw7tOQJ224pWJ
 4xePwtGyj4raAeczOcBQbKKW6hSH9iz7E5XUdpJqO3iZ9psILk5XoyO53wwhsLgGcrkCDQRO
 kueGARAAz5wNYsv5a9z1wuEDY5dn+Aya7s1tgqN+2HVTI64F3l6Yg753hF8UzTZcVMi3gzHC
 ECvKGwpBBwDiJA2V2RvJ6+Jis8paMtONFdPlwPaWlbOv4nHuZfsidXkk7PVCr4/6clZggGNQ
 qEjTe7Hz2nnwJiKXbhmnKfYXlxftT6KdjyUkgHAs8Gdz1nQCf8NWdQ4P7TAhxhWdkAoOIhc4
 OQapODd+FnBtuL4oCG0c8UzZ8bDZVNR/rYgfNX54FKdqbM84FzVewlgpGjcUc14u5Lx/jBR7
 ttZv07ro88Ur9GR6o1fpqSQUF/1V+tnWtMQoDIna6p/UQjWiVicQ2Tj7TQgFr4Fq8ZDxRb10
 Zbeds+t+45XlRS9uexJDCPrulJ2sFCqKWvk3/kf3PtUINDR2G4k228NKVN/aJQUGqCTeyaWf
 fU9RiJU+sw/RXiNrSL2q079MHTWtN9PJdNG2rPneo7l0axiKWIk7lpSaHyzBWmi2Arj/nuHf
 Maxpc708aCecB2p4pUhNoVMtjUhKD4+1vgqiWKI6OsEyZBRIlW2RRcysIwJ648MYejvf1dzv
 mVweUa4zfIQH/+G0qPKmtst4t/XLjE/JN54XnOD/TO1Fk0pmJyASbHJQ0EcecEodDHPWP6bM
 fQeNlm1eMa7YosnXwbTurR+nPZk+TYPndbDf1U0j8n0AEQEAAYkCHwQYAQIACQUCTpLnhgIb
 DAAKCRC9JbEEBrRwSTe1EACA74MWlvIhrhGWd+lxbXsB+elmL1VHn7Ovj3qfaMf/WV3BE79L
 5A1IDyp0AGoxv1YjgE1qgA2ByDQBLjb0yrS1ppYqQCOSQYBPuYPVDk+IuvTpj/4rN2v3R5RW
 d6ozZNRBBsr4qHsnCYZWtEY2pCsOT6BE28qcbAU15ORMq0nQ/yNh3s/WBlv0XCP1gvGOGf+x
 UiE2YQEsGgjs8v719sguok8eADBbfmumerh/8RhPKRuTWxrXdNq/pu0n7hA6Btx7NYjBnnD8
 lV8Qlb0lencEUBXNFDmdWussMAlnxjmKhZyb30m1IgjFfG30UloZzUGCyLkr/53JMovAswmC
 IHNtXHwb58Ikn1i2U049aFso+WtDz4BjnYBqCL1Y2F7pd8l2HmDqm2I4gubffSaRHiBbqcSB
 lXIjJOrd6Q66u5+1Yv32qk/nOL542syYtFDH2J5wM2AWvfjZH1tMOVvVMu5Fv7+0n3x/9shY
 ivRypCapDfcWBGGsbX5eaXpRfInaMTGaU7wmWO44Z5diHpmQgTLOrN9/MEtdkK6OVhAMVenI
 w1UnZnA+ZfaZYShi5oFTQk3vAz7/NaA5/bNHCES4PcDZw7Y/GiIh/JQR8H1JKZ99or9LjFeg
 HrC8YQ1nzkeDfsLtYM11oC3peHa5AiXLmCuSC9ammQ3LhkfET6N42xTu2A==
Message-ID: <d7a42300-6c67-70c4-4c90-5f05c65c421c@suse.com>
Date:   Fri, 22 Nov 2019 13:08:37 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.2.0
MIME-Version: 1.0
In-Reply-To: <1574424258-138975-1-git-send-email-chenwandun@huawei.com>
Content-Type: text/plain; charset=iso-8859-2
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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?

thanks,
-- 
js
suse labs