This is a note to let you know that I've just added the patch titled serial: max310x: fail probe if clock crystal is unstable to the 6.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-max310x-fail-probe-if-clock-crystal-is-unstable.patch and it can be found in the queue-6.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8afa6c6decea37e7cb473d2c60473f37f46cea35 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> Date: Tue, 16 Jan 2024 16:30:00 -0500 Subject: serial: max310x: fail probe if clock crystal is unstable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> commit 8afa6c6decea37e7cb473d2c60473f37f46cea35 upstream. 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: 4cf9a888fd3c ("serial: max310x: Check the clock readiness") Cc: stable@xxxxxxxxxxxxxxx Suggested-by: Jan Kundrát <jan.kundrat@xxxxxxxxx> Link: https://www.spinics.net/lists/linux-serial/msg35773.html Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240116213001.3691629-4-hugo@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/max310x.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -587,7 +587,7 @@ static int max310x_update_best_err(unsig 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 de } 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 * { 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 * } 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++) { Patches currently in stable-queue which might be from hvilleneuve@xxxxxxxxxxxx are queue-6.7/serial-max310x-fail-probe-if-clock-crystal-is-unstable.patch queue-6.7/serial-max310x-prevent-infinite-while-loop-in-port-startup.patch queue-6.7/serial-max310x-set-default-value-when-reading-clock-ready-bit.patch queue-6.7/serial-max310x-improve-crystal-stable-clock-detection.patch