Messages in this thread Patch in this message | | | Date | Wed, 16 Mar 2011 14:18:17 -0700 | From | Yinghai Lu <> | Subject | [PATCH] watchdog, SP5100: Check if firmware has set correct value in tcobase. |
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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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