kern/106645: uart device description in 7-CURRENT is sometimes overwritten

[Eygene Ryabinkin]

>Number:         106645
>Category:       kern
>Synopsis:       uart device description in 7-CURRENT is sometimes overwritten
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Dec 12 15:00:17 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Eygene Ryabinkin
>Release:        FreeBSD 7.0-CURRENT i386
>Organization:
Code Labs
>Environment:
System: FreeBSD XXX 7.0-CURRENT FreeBSD 7.0-CURRENT #2: Sun Dec 10 21:49:11 MSK 2006 root at XXX:/usr/src/sys/i386/compile/XXX-7 i386
>Description:
The uart driver sets PCMCIA card description (for example, in uart_bus_pci.c),
but it is the overwritten by the base ns8250 code in uart_dev_ns8250.c.
>How-To-Repeat:
Take some PCMCIA card that is supported by the uart driver and insert it.
Then watch for the kernel messages.
>Fix:
Simple patch: check if description is already here.

--- uart_dev_ns8250.c.orig	Sun Dec 10 21:47:23 2006
+++ uart_dev_ns8250.c	Sun Dec 10 21:48:47 2006
@@ -634,7 +634,9 @@
 		uart_setreg(bas, REG_MCR, mcr);
 		uart_barrier(bas);
 		sc->sc_rxfifosz = sc->sc_txfifosz = 1;
-		device_set_desc(sc->sc_dev, "8250 or 16450 or compatible");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev,
+			    "8250 or 16450 or compatible");
 		return (0);
 	}
 
@@ -694,20 +696,25 @@
  describe:
 	if (count >= 14 && count <= 16) {
 		sc->sc_rxfifosz = 16;
-		device_set_desc(sc->sc_dev, "16550 or compatible");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev, "16550 or compatible");
 	} else if (count >= 28 && count <= 32) {
 		sc->sc_rxfifosz = 32;
-		device_set_desc(sc->sc_dev, "16650 or compatible");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev, "16650 or compatible");
 	} else if (count >= 56 && count <= 64) {
 		sc->sc_rxfifosz = 64;
-		device_set_desc(sc->sc_dev, "16750 or compatible");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev, "16750 or compatible");
 	} else if (count >= 112 && count <= 128) {
 		sc->sc_rxfifosz = 128;
-		device_set_desc(sc->sc_dev, "16950 or compatible");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev, "16950 or compatible");
 	} else {
 		sc->sc_rxfifosz = 16;
-		device_set_desc(sc->sc_dev,
-		    "Non-standard ns8250 class UART with FIFOs");
+		if (device_get_desc(sc->sc_dev) == NULL)
+			device_set_desc(sc->sc_dev,
+			    "Non-standard ns8250 class UART with FIFOs");
 	}
 
 	/*
>Release-Note:
>Audit-Trail:
>Unformatted: