Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1514ab09edb071345fe17cd230c97f9e72c9478e Commit: 1514ab09edb071345fe17cd230c97f9e72c9478e Parent: 80492cc797ea15572de8eac766cbf606626ee338 Author: Mikael Pettersson <[EMAIL PROTECTED]> AuthorDate: Tue Jul 24 00:25:59 2007 +0200 Committer: H. Peter Anvin <[EMAIL PROTECTED]> CommitDate: Wed Jul 25 12:02:21 2007 -0700
[x86 setup] APM detection logic bug fix Starting with kernel 2.6.23-rc1, the i386 APM driver fails on several of my machines with the message: apm: BIOS not found This happens because of a bug in the i386 boot code rewrite from assembler to C. The original assembly code had the following code in its APM BIOS presence test (boot/setup.S): andw $0x02, %cx # Is 32 bit supported? je done_apm_bios # No 32-bit, no (good) APM BIOS That is, the code bails out if bit 2 is zero. In the new C version, this is coded as (boot/apm.c): if (cx & 0x02) /* 32 bits supported? */ return -1; Here we see that the test has been accidentally inverted. The fix is to negate the test. I've verified that this allows the APM driver to work again on my affected machines. Signed-off-by: Mikael Pettersson <[EMAIL PROTECTED]> Signed-off-by: H. Peter Anvin <[EMAIL PROTECTED]> --- arch/i386/boot/apm.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/i386/boot/apm.c b/arch/i386/boot/apm.c index a34087c..8be3f56 100644 --- a/arch/i386/boot/apm.c +++ b/arch/i386/boot/apm.c @@ -40,7 +40,7 @@ int query_apm_bios(void) if (bx != 0x504d) /* "PM" signature */ return -1; - if (cx & 0x02) /* 32 bits supported? */ + if (!(cx & 0x02)) /* 32 bits supported? */ return -1; /* Disconnect first, just in case */ - To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html