Subject: Re: [PATCH] Fix RTAS watchdog driver temperature read functionality

From: Adrian Reber <[email-masked]>
Date: Tue, 24 Mar 2009 12:45:05 +0100

On Tue, Mar 24, 2009 at 03:27:18PM +1100, Benjamin Herrenschmidt wrote:
> On Mon, 2009-03-16 at 13:35 +0100, Adrian Reber wrote:
> > Using the RTAS watchdog driver to read out the temperature crashes
> > on a PXCAB:
> > 
> > Unable to handle kernel paging request for data at address 0xfe347b50
> > Faulting instruction address: 0xc00000000001af64
> > Oops: Kernel access of bad area, sig: 11 [#1]
> > 
> > This (removing "(void *)__pa") fixes it.
> 
> Looks correct, but why not use rtas_get_sensor() instead ? (Exported by
> arch/powerpc/kernel/rtas.c

Ah, you mean something like?

 drivers/watchdog/wdrtas.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/wdrtas.c b/drivers/watchdog/wdrtas.c
index 5d3b1a8..af2bbfa 100644
--- a/drivers/watchdog/wdrtas.c
+++ b/drivers/watchdog/wdrtas.c
@@ -214,16 +214,14 @@ static void wdrtas_timer_keepalive(void)
  */
 static int wdrtas_get_temperature(void)
 {
-	long result;
+	int result;
 	int temperature = 0;
 
-	result = rtas_call(wdrtas_token_get_sensor_state, 2, 2,
-			   (void *)__pa(&temperature),
-			   WDRTAS_THERMAL_SENSOR, 0);
+	result = rtas_get_sensor(WDRTAS_THERMAL_SENSOR, 0, &temperature);
 
 	if (result < 0)
 		printk(KERN_WARNING "wdrtas: reading the thermal sensor "
-		       "faild: %li\n", result);
+		       "faild: %i\n", result);
 	else
 		temperature = ((temperature * 9) / 5) + 32; /* fahrenheit */

		Adrian