Ubuntu
linux-hwe-edge package

  1. Xenial (16.04)
  2. Bug #1734147
  3. Comment #529

Comment 529 for bug 1734147

Revision history for this message
Mika Westerberg (mika-westerberg) wrote :

#528

Keep in mind that there are two *separate* issues:

1. Bug off-by-one bug in intel-spi driver that causes CMP bit to accidentally set to 1. This results BIOS
   being read-only. The bug was fixed by 9d63f17661e2 ("spi-nor: intel-spi: Fix broken software sequencing
   codes") in september.

2. Some Lenovo Thinkpad Yoga BIOSes reset to default settings if their BCR register is touched. This BCR
   handling is in a different driver (drivers/mfd/lpc_ich.c). This issue has been fixed by commit
   d9018976cdb6 ("mfd: lpc_ich: Do not touch SPI-NOR write protection bit on Haswell/Broadwell") in july.

So in order to have a kernel that is free from both issues, you need to disable the intel-spi driver (for reasons being that it is not supposed to be enabled for normal users anyway) and then cherry-pick commit d9018976cdb6 to make sure the other issue does not happen.