linux-kernel - Re: [PATCH 4/8] tty: atmel_serial: Use devm_clk_get

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Message-ID: <c54434e3-1fb8-4491-b24f-2167786fe84c@bootlin.com>
Date: Thu, 22 Aug 2024 15:28:40 +0200
From: Richard GENOUD <richard.genoud@...tlin.com>
To: Lei Liu <liulei.rjpt@...o.com>
Cc: Paul Cercueil <paul@...pouillou.net>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Jiri Slaby <jirislaby@...nel.org>, Thierry Reding
 <thierry.reding@...il.com>, Jonathan Hunter <jonathanh@...dia.com>,
 Kunihiko Hayashi <hayashi.kunihiko@...ionext.com>,
 Masami Hiramatsu <mhiramat@...nel.org>,
 Nicolas Ferre <nicolas.ferre@...rochip.com>,
 Alexandre Belloni <alexandre.belloni@...tlin.com>,
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 <liviu.dudau@....com>, Sudeep Holla <sudeep.holla@....com>,
 Lorenzo Pieralisi <lpieralisi@...nel.org>, Andreas Färber
 <afaerber@...e.de>, Manivannan Sadhasivam
 <manivannan.sadhasivam@...aro.org>,
 Patrice Chotard <patrice.chotard@...s.st.com>,
 Maxime Coquelin <mcoquelin.stm32@...il.com>,
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 Erwan Le Ray <erwan.leray@...s.st.com>, linux-mips@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
 linux-tegra@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
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 opensource.kernel@...o.com
Subject: Re: [PATCH 4/8] tty: atmel_serial: Use devm_clk_get_enabled() helpers

Le 22/08/2024 à 05:39, Lei Liu a écrit :
> The devm_clk_get_enabled() helpers:
>      - call devm_clk_get()
>      - call clk_prepare_enable() and register what is needed in order to
>       call clk_disable_unprepare() when needed, as a managed resource.
> 
> This simplifies the code and avoids calls to clk_disable_unprepare().
> 
> Signed-off-by: Lei Liu <liulei.rjpt@...o.com>
> ---
>   drivers/tty/serial/atmel_serial.c | 8 +-------
>   1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 09b246c9e389..209f3d41a17c 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2910,14 +2910,11 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   	atomic_set(&atmel_port->tasklet_shutdown, 0);
>   	spin_lock_init(&atmel_port->lock_suspended);
>   
> -	atmel_port->clk = devm_clk_get(&pdev->dev, "usart");
> +	atmel_port->clk = devm_clk_get_enabled(&pdev->dev, "usart");
>   	if (IS_ERR(atmel_port->clk)) {
>   		ret = PTR_ERR(atmel_port->clk);
>   		goto err;
>   	}
> -	ret = clk_prepare_enable(atmel_port->clk);
> -	if (ret)
> -		goto err;
>   
>   	atmel_port->gclk = devm_clk_get_optional(&pdev->dev, "gclk");
>   	if (IS_ERR(atmel_port->gclk)) {
> @@ -2968,15 +2965,12 @@ static int atmel_serial_probe(struct platform_device *pdev)
>   	 * The peripheral clock can now safely be disabled till the port
>   	 * is used
>   	 */
> -	clk_disable_unprepare(atmel_port->clk);
> -
Why removing this ?
This is not an error path.

>   	return 0;
>   
>   err_add_port:
>   	kfree(atmel_port->rx_ring.buf);
>   	atmel_port->rx_ring.buf = NULL;
>   err_clk_disable_unprepare:
> -	clk_disable_unprepare(atmel_port->clk);
>   	clear_bit(atmel_port->uart.line, atmel_ports_in_use);
>   err:
>   	return ret;

Thanks,
Richard.