Without checking the return value of get_edd_info() and adding the
entry only in the success case, 6 devices show up under
/sys/firmware/edd/, no matter how many devices are actually present.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add a kernel parameter option to 'edd' to enable/disable BIOS Enhanced Disk
Drive Services. CONFIG_EDD_OFF disables EDD while still compiling EDD into
the kernel. Default behavior can be forced using 'edd=on' or 'edd=off' as
a kernel parameter.
[akpm@linux-foundation.org: fix kernel-parameters.txt]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove old comments that include the old arch/i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tell the user to specify edd=off in the case of EDD probing hangs.
Per LKML discussion.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unnecessary capitals are shouting; no need for it here.
Thus, change "OK" to "ok" and add a space.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On early boot, probing the Bios for EDD happens without any message.
Enhanced Disk Drive Services (EDD) is a mechanism to match x86 BIOS device
names (int13 device 80h) to Linux device names (e.g. /dev/sda, /dev/hda)
There are buggy Bios out there having problems with EDD. This can be problems
with the Bios itself or with addon cards, too.
This patch is adds an informational message on early boot.
CONFIG_EDD is not set with defconfig, but with allmodconfig (i.e. CONFIG_EDD=m)
so the EDD probe may be active on early boot on many systems nowadays.
I can tell, that the probe is active on SuSE distro and with that I have seen
more than one system hanging endlessly with those "black screen with a blinking
cursor in the the upper left" on installation, making it difficult for the end-
user to find out, what`s the issue.
For sure I have seen this on FujitsuSiemens PCs with i810 and with i815 chipset.
This one also honours the "quiet" bootparam.
Also see:
http://marc.info/?l=linux-kernel&m=119781937207969&w=2http://marc.info/?l=linux-kernel&m=119783934032326&w=2http://marc.info/?l=linux-kernel&m=119783678529100&w=2
Signed-off-by: Roland Kletzing <devzero@web.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
asm() statements need to be volatile when:
a. They have side effects (other than value returned).
b. When the value returned can vary over time.
c. When they have ordering constraints that cannot be expressed to gcc.
In particular, the keyboard and timer reads were violating constraint (b),
which resulted in the keyboard/timeout poll getting
loop-invariant-removed when compiling with gcc 4.2.0.
Thanks to an anonymous bug reporter for pointing this out.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
When filling in the MBR signature array, the setup code failed to advance
boot_params.edd_mbr_sig_buf_entries, which resulted in the valid data
being ignored.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
At least one machine has been identified in the field which advertises
EDD for all drives but locks up if one attempts an extended read from
a non-primary drive.
The MBR is always at CHS 0-0-1, so there is no reason to use an
extended read, other than the possibility that the BIOS cannot handle
it.
Although this might break as many machines as it fixes (a small number
either way), the current state is a regression but the reverse is not.
Therefore revert to the previous state of not using extended read.
Quite probably the Right Thing to do is to read using plain (CHS) read
and extended read on failure, but that change would definitely have to
go through -mm first.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add a missing =m constraint to the EDD-probing code, that could have
caused improper dead-code elimination.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Some BIOSes require that sector buffers not cross 64K
boundaries. As a result, we compute a dynamic address on the
setup heap. Unfortunately, this address computation was just
totally wrong.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Probe EDD and MBR signatures, in order to make it easier to map
physical hard drives to BIOS drives.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Beulich