This is a note to let you know that I've just added the patch titled
serial: core: Add UPIO_UNKNOWN constant for unknown port type
to the 6.1-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-core-add-upio_unknown-constant-for-unknown-po.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e60abf4c53fa88756e92df98cfe5cba30accd0dd
Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Date: Mon Mar 4 14:27:03 2024 +0200
serial: core: Add UPIO_UNKNOWN constant for unknown port type
[ Upstream commit 79d713baf63c8f23cc58b304c40be33d64a12aaf ]
In some APIs we would like to assign the special value to iotype
and compare against it in another places. Introduce UPIO_UNKNOWN
for this purpose.
Note, we can't use 0, because it's a valid value for IO port access.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240304123035.758700-3-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 13bf20242b61a..1c9b3f27f2d36 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -467,6 +467,7 @@ struct uart_port {
unsigned char iotype; /* io access style */
unsigned char quirks; /* internal quirks */
+#define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */
#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
#define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
