tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements

[PATCH] tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements

Posted by Douglas Anderson 3 years, 8 months ago

When we multiply an unsigned int by a u32 we still end up with an
unsigned int. That means we should specify "%u" not "%lu" in the
format code.

NOTE: this fix was chosen instead of somehow promoting the value to
"unsigned long" since the max baud rate from the earlier call to
uart_get_baud_rate() is 4000000 and the max sampling rate is 32.
4000000 * 32 = 0x07a12000, not even close to overflowing 32-bits.

Fixes: c474c775716e ("tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/tty/serial/qcom_geni_serial.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index f754619451dc..f7c1f1807040 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1033,12 +1033,12 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 		sampling_rate, &clk_div);
 	if (!clk_rate) {
 		dev_err(port->se.dev,
-			"Couldn't find suitable clock rate for %lu\n",
+			"Couldn't find suitable clock rate for %u\n",
 			baud * sampling_rate);
 		goto out_restart_rx;
 	}
 
-	dev_dbg(port->se.dev, "desired_rate-%lu, clk_rate-%lu, clk_div-%u\n",
+	dev_dbg(port->se.dev, "desired_rate-%u, clk_rate-%lu, clk_div-%u\n",
 			baud * sampling_rate, clk_rate, clk_div);
 
 	uport->uartclk = clk_rate;
-- 
2.37.1.455.g008518b4e5-goog

Re: [PATCH] tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements

Posted by Jiri Slaby 3 years, 8 months ago

On 02. 08. 22, 22:23, Douglas Anderson wrote:
> When we multiply an unsigned int by a u32 we still end up with an
> unsigned int. That means we should specify "%u" not "%lu" in the
> format code.
> 
> NOTE: this fix was chosen instead of somehow promoting the value to
> "unsigned long" since the max baud rate from the earlier call to
> uart_get_baud_rate() is 4000000 and the max sampling rate is 32.
> 4000000 * 32 = 0x07a12000, not even close to overflowing 32-bits.

Acked-by: Jiri Slaby <jirislaby@kernel.org>

I wonder, how this became unnoticed by the 0day bot?

> Fixes: c474c775716e ("tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.")
> Reported-by: Mark Brown <broonie@kernel.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
>   drivers/tty/serial/qcom_geni_serial.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index f754619451dc..f7c1f1807040 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -1033,12 +1033,12 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
>   		sampling_rate, &clk_div);
>   	if (!clk_rate) {
>   		dev_err(port->se.dev,
> -			"Couldn't find suitable clock rate for %lu\n",
> +			"Couldn't find suitable clock rate for %u\n",
>   			baud * sampling_rate);
>   		goto out_restart_rx;
>   	}
>   
> -	dev_dbg(port->se.dev, "desired_rate-%lu, clk_rate-%lu, clk_div-%u\n",
> +	dev_dbg(port->se.dev, "desired_rate-%u, clk_rate-%lu, clk_div-%u\n",
>   			baud * sampling_rate, clk_rate, clk_div);
>   
>   	uport->uartclk = clk_rate;


-- 
js
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