At Tue, 08 Nov 2011 04:57:42 +0100,Dear Takashi,
Ãric Piel wrote:
Op 03-11-11 13:09, Takashi Iwai schreef:In some weird situation, HP DriveGuard chip can't read ODR valueHi Takashi,
correctly, and it results in a zero-division Oops in lis3lv02d driver.
This patch fixes the Oops by checking the value appopriately, and skips
if any weird value is read.
Actually, a similar patch already just landed in linus' tree:
1510dd5954 (lis3lv02d: avoid divide by zero due to unchecked)
However, in the patch applied, the device is disabled (until next
reboot) while in yours, the sleep is just skipped. Does it work again
after the read of odr fails? If so, maybe I could improve the current
version by, after the odr read fails, sleeping a long and safe time and
then trying to read the odr again. Then if it fails again, we give up,
otherwise the device can be used again.
I guess it's possible to use the device afterward. The possible
reason is either the chip is set to an invalid mode or ACPI isn't set
up properly. But this path usually means that ACPI does work more or
less since you could read WHOAMI.
Do you have such a device yourself? Could you let me know if after a
failing read of the odr, the device keeps working?
I have a machine but I'm not quite sure how to reproduce this error.
It happened casually during the installation of a new system, so it's
not so trivial to switch the module during it...