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Subject[PATCH] watchdog, SP5100: Check if firmware has set correct value in tcobase.


Stefano found SP5100 TCO watchdog driver using wrong address.

[ 9.148536] SP5100 TCO timer: SP5100 TCO WatchDog Timer Driver v0.01
[ 9.148628] DEBUG __ioremap_caller WARNING address=b8fe00 size=8 valid=1 reserved=1

and e820 said that range is RAM.

We should check if we can use that reading out. BIOS could just program wrong address there.

-v2: Mike pointed out one path need one release.

Reported-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by:Yinghai Lu <yinghai@kernel.org>
Acked-by: Mike Waychison <mikew@google.com>

---
drivers/watchdog/sp5100_tco.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
Index: linux-2.6/drivers/watchdog/sp5100_tco.c
===================================================================
--- linux-2.6.orig/drivers/watchdog/sp5100_tco.c
+++ linux-2.6/drivers/watchdog/sp5100_tco.c
@@ -42,6 +42,7 @@
#define PFX TCO_MODULE_NAME ": "

/* internal variables */
+static u32 tcobase_phys;
static void __iomem *tcobase;
static unsigned int pm_iobase;
static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */
@@ -305,10 +306,16 @@ static unsigned char __devinit sp5100_tc
/* Low three bits of BASE0 are reserved. */
val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8);

+ if (request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE, "SP5100 TCO")) {
+ printk(KERN_ERR PFX "mmio address 0x%04x already in use\n", val);
+ goto unreg_region;
+ }
+ tcobase_phys = val;
+
tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
if (tcobase == 0) {
printk(KERN_ERR PFX "failed to get tcobase address\n");
- goto unreg_region;
+ goto unreg_mem_region;
}

/* Enable watchdog decode bit */
@@ -346,7 +353,8 @@ static unsigned char __devinit sp5100_tc
/* Done */
return 1;

- iounmap(tcobase);
+unreg_mem_region:
+ release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
unreg_region:
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
exit:
@@ -401,6 +409,7 @@ static int __devinit sp5100_tco_init(str

exit:
iounmap(tcobase);
+ release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
return ret;
}
@@ -414,6 +423,7 @@ static void __devexit sp5100_tco_cleanup
/* Deregister */
misc_deregister(&sp5100_tco_miscdev);
iounmap(tcobase);
+ release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
}


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