6.1-stable patches

added patches:
	serial-8250-fix-panic-due-to-pslverr.patch

diff --git a/queue-6.1/serial-8250-fix-panic-due-to-pslverr.patch b/queue-6.1/serial-8250-fix-panic-due-to-pslverr.patch
new file mode 100644 (file)
index 0000000..fac1295
--- /dev/null
+++ b/queue-6.1/serial-8250-fix-panic-due-to-pslverr.patch
@@ -0,0 +1,61 @@
+From 7f8fdd4dbffc05982b96caf586f77a014b2a9353 Mon Sep 17 00:00:00 2001
+From: Yunhui Cui <cuiyunhui@bytedance.com>
+Date: Wed, 23 Jul 2025 10:33:22 +0800
+Subject: serial: 8250: fix panic due to PSLVERR
+
+From: Yunhui Cui <cuiyunhui@bytedance.com>
+
+commit 7f8fdd4dbffc05982b96caf586f77a014b2a9353 upstream.
+
+When the PSLVERR_RESP_EN parameter is set to 1, the device generates
+an error response if an attempt is made to read an empty RBR (Receive
+Buffer Register) while the FIFO is enabled.
+
+In serial8250_do_startup(), calling serial_port_out(port, UART_LCR,
+UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes
+dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter
+function enables the FIFO via serial_out(p, UART_FCR, p->fcr).
+Execution proceeds to the serial_port_in(port, UART_RX).
+This satisfies the PSLVERR trigger condition.
+
+When another CPU (e.g., using printk()) is accessing the UART (UART
+is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) ==
+(lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter
+dw8250_force_idle().
+
+Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock
+to fix this issue.
+
+Panic backtrace:
+[    0.442336] Oops - unknown exception [#1]
+[    0.442343] epc : dw8250_serial_in32+0x1e/0x4a
+[    0.442351]  ra : serial8250_do_startup+0x2c8/0x88e
+...
+[    0.442416] console_on_rootfs+0x26/0x70
+
+Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround")
+Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/
+Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
+Reviewed-by: John Ogness <john.ogness@linutronix.de>
+Cc: stable <stable@kernel.org>
+Link: https://lore.kernel.org/r/20250723023322.464-2-cuiyunhui@bytedance.com
+[ Applied fix to serial8250_do_startup() instead of serial8250_initialize() ]
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/8250/8250_port.c |    3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/tty/serial/8250/8250_port.c
++++ b/drivers/tty/serial/8250/8250_port.c
+@@ -2370,9 +2370,8 @@ int serial8250_do_startup(struct uart_po
+       /*
+        * Now, initialize the UART
+        */
+-      serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+-
+       spin_lock_irqsave(&port->lock, flags);
++      serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+       if (up->port.flags & UPF_FOURPORT) {
+               if (!up->port.irq)
+                       up->port.mctrl |= TIOCM_OUT1;

diff --git a/queue-6.1/series b/queue-6.1/series
index 6604ed65216bc765b40579ff827a156b244a0f86..cf40bd35b8f156efe89516e63eb378560f7cd0d9 100644 (file)
--- a/queue-6.1/series
+++ b/queue-6.1/series
@@ -265,3 +265,4 @@ media-uvcvideo-do-not-mark-valid-metadata-as-invalid.patch
 tools-nolibc-fix-spelling-of-fd_setbitmask-in-fd_-macros.patch
 hid-magicmouse-avoid-setting-up-battery-timer-when-not-needed.patch
 hid-apple-avoid-setting-up-battery-timer-for-devices-without-battery.patch
+serial-8250-fix-panic-due-to-pslverr.patch