drivers/char: add console=ehci as an alias for console=dbgp

Make it consistent with console=xhci.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

docs/misc/xen-command-line.pandoc

@@ -409,7 +409,7 @@ The following are examples of correct specifications:
 Specify the size of the console ring buffer.
 
 ### console
-> `= List of [ vga | com1[H,L] | com2[H,L] | pv | dbgp | xhci | none ]`
+> `= List of [ vga | com1[H,L] | com2[H,L] | pv | dbgp | ehci | xhci | none ]`
 
 > Default: `console=com1,vga`
 
@@ -428,7 +428,7 @@ cleared.  This allows a single port to be shared by two subsystems
 `pv` indicates that Xen should use Xen's PV console. This option is
 only available when used together with `pv-in-pvh`.
 
-`dbgp` indicates that Xen should use a USB2 debug port.
+`dbgp` or `ehci` indicates that Xen should use a USB2 debug port.
 
 `xhci` indicates that Xen should use a USB3 debug port.
 

xen/drivers/char/serial.c

@@ -311,6 +311,12 @@ int __init serial_parse_handle(const char *conf)
         goto common;
     }
 
+    if ( !strncmp(conf, "ehci", 4) && (!conf[4] || conf[4] == ',') )
+    {
+        handle = SERHND_DBGP;
+        goto common;
+    }
+
     if ( !strncmp(conf, "xhci", 4) && (!conf[4] || conf[4] == ',') )
     {
         handle = SERHND_XHCI;