-
Bjorn Helgaas authored
commit 13cfc732 upstream. Neither soft poweroff (transition to ACPI power state S5) nor suspend-to-RAM (transition to state S3) works on the Macbook Pro 11,4 and 11,5. The problem is related to the [mem 0x7fa00000-0x7fbfffff] space. When we use that space, e.g., by assigning it to the 00:1c.0 Root Port, the ACPI Power Management 1 Control Register (PM1_CNT) at [io 0x1804] doesn't work anymore. Linux does a soft poweroff (transition to S5) by writing to PM1_CNT. The theory about why this doesn't work is: - The write to PM1_CNT causes an SMI - The BIOS SMI handler depends on something in [mem 0x7fa00000-0x7fbfffff] - When Linux assigns [mem 0x7fa00000-0x7fbfffff] to the 00:1c.0 Port, it covers up whatever the SMI handler uses, so the SMI handler no longer works correctly Reserve the [mem 0x7fa00000-0x7fbfffff] space so we don't assign it to anything. This is voodoo programming, since we don't know what the real conflict is, but we've failed to find the root cause. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=103211 Tested-by: thejoe@gmail.com Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Chen Yu <yu.c.chen@intel.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
13b2f9f9