On Sun, Jul 01, 2018 at 12:15:46PM +0200, Hans de Goede wrote: > There have been several reports of LPM related hard freezes about once > a day on multiple Lenovo 50 series models. Strange enough these reports > where not disk model specific as LPM issues usually are and some users > with the exact same disk + laptop where seeing them while other users > where not seeing these issues. > > It turns out that enabling LPM triggers a firmware bug somewhere, which > has been fixed in later BIOS versions. > > This commit adds a new ahci_broken_lpm() function and a new ATA_FLAG_NO_LPM > for dealing with this. > > The ahci_broken_lpm() function contains DMI match info for the 4 models > which are known to be affected by this and the DMI BIOS date field for > known good BIOS versions. If the BIOS date is older then the one in the > table LPM will be disabled and a warning will be printed. > > Note the BIOS dates are for known good versions, some older versions may > work too, but we don't know for sure, the table is using dates from BIOS > versions for which users have confirmed that upgrading to that version > makes the problem go away. > > Unfortunately I've been unable to get hold of the reporter who reported > that BIOS version 2.35 fixed the problems on the W541 for him. I've been > able to verify the DMI_SYS_VENDOR and DMI_PRODUCT_VERSION from an older > dmidecode, but I don't know the exact BIOS date as reported in the DMI. > Lenovo keeps a changelog with dates in their release notes, but the > dates there are the release dates not the build dates which are in DMI. > So I've chosen to set the date to which we compare to one day past the > release date of the 2.34 BIOS. I plan to fix this with a follow up > commit once I've the necessary info. > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Applied to libata/for-4.18-fixes. Thanks. -- tejun
