Re: [PATCH v2] serial: add PORT_GENERIC definition

From: Jiri Slaby
Date: Mon Oct 09 2023 - 02:03:57 EST


On 08. 10. 23, 2:18, Max Filippov wrote:
Current pattern in the linux kernel is that every new serial driver adds
one or more new PORT_ definitions because uart_ops::config_port()
callback documentation prescribes setting port->type according to the
type of port found, or to PORT_UNKNOWN if no port was detected.

When the specific type of the port is not important to the userspace
there's no need for a unique PORT_ value, but so far there's no suitable
identifier for that case.

Provide generic port type identifier other than PORT_UNKNOWN for ports
which type is not important to userspace.

Oh, finally someone submitted this.

Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
In that case metoo [1]:
Suggested-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
and
Reviewed-by: Jiri Slaby <jirislaby@xxxxxxxxxx>

[1] https://lore.kernel.org/all/75375f8d-e157-a364-3da5-9c8d5b832927@xxxxxxxxxx/

Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
Changes v1->v2:
- move to the end of PORT_ definition list
- rename to PORT_GENERIC

include/uapi/linux/serial_core.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index add349889d0a..0a5090e08657 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -245,4 +245,7 @@
/* Sunplus UART */
#define PORT_SUNPLUS 123
+/* Generic type identifier for ports which type is not important to userspace. */
+#define PORT_GENERIC (-1)
+
#endif /* _UAPILINUX_SERIAL_CORE_H */

--
js
suse labs