Update documentation for linuxspi extended parameter disable_no_cs

src/avrdude.1

@@ -1217,6 +1217,14 @@ specific.
 .Pp
 When not provided, driver/OS default value will be used.
 .El
+.It Ar linuxspi
+Extended parameter:
+.Bl -tag -offset indent -width indent
+.It Ar disable_no_cs
+Ensures the programmer does not use the SPI_NO_CS bit for the SPI
+driver. This parameter is useful for kernels that do not support
+the CS line being managed outside the application.
+.El
 .El
 .Sh FILES
 .Bl -tag -offset indent -width /dev/ppi0XXX

src/doc/avrdude.texi

@@ -1111,6 +1111,16 @@ specific.
 When not provided, driver/OS default value will be used.
 @end table
 
+@cindex @code{-x} linuxspi
+@item linuxspi
+Extended parameter:
+@table @code
+@item @samp{disable_no_cs}
+Ensures the programmer does not use the SPI_NO_CS bit for the SPI
+driver. This parameter is useful for kernels that do not support
+the CS line being managed outside the application.
+@end table
+
 @end table
 
 @page