Le 14/04/2025 à 10:58, Greg KH a écrit :
On Mon, Apr 14, 2025 at 07:54:12AM +0000, Thierry Bultel wrote:
Hi Greg,
-----Original Message-----
From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Sent: vendredi 11 avril 2025 16:57
To: Thierry Bultel <thierry.bultel.yh@xxxxxxxxxxxxxx>
Cc: thierry.bultel@xxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx;
geert@xxxxxxxxxxxxxx; Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx>; Wolfram
Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
linux-serial@xxxxxxxxxxxxxxx
Subject: Re: [PATCH v7 10/13] serial: sh-sci: Add support for RZ/T2H SCI
On Thu, Apr 03, 2025 at 11:29:12PM +0200, Thierry Bultel wrote:
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -231,6 +231,9 @@
/* Sunplus UART */
#define PORT_SUNPLUS 123
+/* SH-SCI */
+#define PORT_RSCI 124
Why do you need to tell userspace about this specific port? Is that a
hard requirement that your userspace tools require? If not, please don't
export this here.
This point has been discussed with Geert and Wolfram.
We cannot use PORT_GENERIC for this IP, and adding the new type
is just keeping consistent with the sh-sci driver.
But, why does userspace need to know this number? And why doesn't
PORT_GENERIC work?
The reason is that the sh-sci driver discriminates internally between
port types.
There are number of locations when it checks for PORT_SCI, PORT_SCIF,
PORT_SCIFA...
T2H SCI needs special handling, too, that is the reason why PORT_GENERIC
cannot work. I just therefore added this new type.
thanks,
greg k-h
