From: Corey Minyard If the ACPI register bit width is zero (an invalid value) assume it is the default spacing. This avoids some coredumps on invalid data and makes some systems work that have broken ACPI data. Signed-off-by: Corey Minyard Signed-off-by: Andrew Morton --- drivers/char/ipmi/ipmi_si_intf.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff -puN drivers/char/ipmi/ipmi_si_intf.c~ipmi-fix-for-handling-bad-acpi-data drivers/char/ipmi/ipmi_si_intf.c --- 25/drivers/char/ipmi/ipmi_si_intf.c~ipmi-fix-for-handling-bad-acpi-data 2005-04-26 20:10:13.950386344 -0700 +++ 25-akpm/drivers/char/ipmi/ipmi_si_intf.c 2005-04-26 20:10:13.955385584 -0700 @@ -1526,8 +1526,17 @@ static int try_init_acpi(int intf_num, s info->irq_setup = NULL; } - regspacings[intf_num] = spmi->addr.register_bit_width / 8; - info->io.regspacing = spmi->addr.register_bit_width / 8; + if (spmi->addr.register_bit_width) { + /* A (hopefully) properly formed register bit width. */ + regspacings[intf_num] = spmi->addr.register_bit_width / 8; + info->io.regspacing = spmi->addr.register_bit_width / 8; + } else { + /* Some broken systems get this wrong and set the value + * to zero. Assume it is the default spacing. If that + * is wrong, too bad, the vendor should fix the tables. */ + regspacings[intf_num] = DEFAULT_REGSPACING; + info->io.regspacing = DEFAULT_REGSPACING; + } regsizes[intf_num] = regspacings[intf_num]; info->io.regsize = regsizes[intf_num]; regshifts[intf_num] = spmi->addr.register_bit_offset; _