Commit 8afa6c6d authored by Hugo Villeneuve's avatar Hugo Villeneuve Committed by Greg Kroah-Hartman
Browse files

serial: max310x: fail probe if clock crystal is unstable 



A stable clock is really required in order to use this UART, so log an
error message and bail out if the chip reports that the clock is not
stable.

Fixes: 4cf9a888 ("serial: max310x: Check the clock readiness")
Cc: stable@vger.kernel.org
Suggested-by: default avatarJan Kundrát <jan.kundrat@cesnet.cz>
Link: https://www.spinics.net/lists/linux-serial/msg35773.html


Signed-off-by: default avatarHugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240116213001.3691629-4-hugo@hugovil.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 93cd256a

drivers/tty/serial/max310x.c

+9 −3
Original line number Diff line number Diff line
@@ -587,7 +587,7 @@ static int max310x_update_best_err(unsigned long f, long *besterr) 
	return 1;

}



static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,

static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,

			       unsigned long freq, bool xtal)

{

	unsigned int div, clksrc, pllcfg = 0;
@@ -657,7 +657,8 @@ static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s, 
		} while (!stable && (++try < MAX310X_XTAL_WAIT_RETRIES));



		if (!stable)

			dev_warn(dev, "clock is not stable yet\n");

			return dev_err_probe(dev, -EAGAIN,

					     "clock is not stable\n");

	}



	return bestfreq;
@@ -1282,7 +1283,7 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty 
{

	int i, ret, fmin, fmax, freq;

	struct max310x_port *s;

	u32 uartclk = 0;

	s32 uartclk = 0;

	bool xtal;



	for (i = 0; i < devtype->nr; i++)
@@ -1360,6 +1361,11 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty 
	}



	uartclk = max310x_set_ref_clk(dev, s, freq, xtal);

	if (uartclk < 0) {

		ret = uartclk;

		goto out_uart;

	}



	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);



	for (i = 0; i < devtype->nr; i++) {