commit: 41adafbd7b84c66c2cdad857b75d5d45032310a6 From: Takahisa Tanaka <mc74hc00@xxxxxxxxx> Date: Mon, 14 Jan 2013 11:01:58 +0900 Subject: watchdog: sp5100_tco: Write back the original value to reserved bits, instead of zero In case of SP5100 or SB7x0 chipsets, the sp5100_tco module writes zero to reserved bits. The module, however, shouldn't depend on specific default value, and should perform a read-merge-write operation for the reserved bits. This patch makes the sp5100_tco module perform a read-merge-write operation on all the chipset (sp5100, sb7x0, sb8x0 or later). Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43176 Signed-off-by: Takahisa Tanaka <mc74hc00@xxxxxxxxx> Tested-by: Paul Menzel <paulepanter@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> --- drivers/watchdog/sp5100_tco.c | 28 ++++++++-------------------- 1 file changed, 8 insertions(+), 20 deletions(-) diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c index 5dfe86e..e3b8f75 100644 --- a/drivers/watchdog/sp5100_tco.c +++ b/drivers/watchdog/sp5100_tco.c @@ -361,7 +361,7 @@ static unsigned char sp5100_tco_setupdevice(void) { struct pci_dev *dev = NULL; const char *dev_name = NULL; - u32 val; + u32 val, tmp_val; u32 index_reg, data_reg, base_addr; /* Match the PCI device */ @@ -497,31 +497,19 @@ static unsigned char sp5100_tco_setupdevice(void) pr_debug("Got 0x%04x from resource tree\n", val); } - /* Restore to the low three bits, if chipset is SB8x0(or later) */ - if (sp5100_tco_pci->revision >= 0x40) { - u8 reserved_bit; - outb(base_addr+0, index_reg); - reserved_bit = inb(data_reg) & 0x7; - val |= (u32)reserved_bit; - } + /* Restore to the low three bits */ + outb(base_addr+0, index_reg); + tmp_val = val | (inb(data_reg) & 0x7); /* Re-programming the watchdog timer base address */ outb(base_addr+0, index_reg); - /* Low three bits of BASE are reserved */ - outb((val >> 0) & 0xff, data_reg); + outb((tmp_val >> 0) & 0xff, data_reg); outb(base_addr+1, index_reg); - outb((val >> 8) & 0xff, data_reg); + outb((tmp_val >> 8) & 0xff, data_reg); outb(base_addr+2, index_reg); - outb((val >> 16) & 0xff, data_reg); + outb((tmp_val >> 16) & 0xff, data_reg); outb(base_addr+3, index_reg); - outb((val >> 24) & 0xff, data_reg); - - /* - * Clear unnecessary the low three bits, - * if chipset is SB8x0(or later) - */ - if (sp5100_tco_pci->revision >= 0x40) - val &= ~0x7; + outb((tmp_val >> 24) & 0xff, data_reg); if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE, dev_name)) { -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html