This is a note to let you know that I've just added the patch titled

    ASPM: Fix pcie devices with non-pcie children

to the 3.3-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     aspm-fix-pcie-devices-with-non-pcie-children.patch
and it can be found in the queue-3.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From c9651e70ad0aa499814817cbf3cc1d0b806ed3a1 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <[email protected]>
Date: Tue, 27 Mar 2012 10:17:41 -0400
Subject: ASPM: Fix pcie devices with non-pcie children

From: Matthew Garrett <[email protected]>

commit c9651e70ad0aa499814817cbf3cc1d0b806ed3a1 upstream.

Since 3.2.12 and 3.3, some systems are failing to boot with a BUG_ON.
Some other systems using the pata_jmicron driver fail to boot because no
disks are detected.  Passing pcie_aspm=force on the kernel command line
works around it.

The cause: commit 4949be16822e ("PCI: ignore pre-1.1 ASPM quirking when
ASPM is disabled") changed the behaviour of pcie_aspm_sanity_check() to
always return 0 if aspm is disabled, in order to avoid cases where we
changed ASPM state on pre-PCIe 1.1 devices.

This skipped the secondary function of pcie_aspm_sanity_check which was
to avoid us enabling ASPM on devices that had non-PCIe children, causing
trouble later on.  Move the aspm_disabled check so we continue to honour
that scenario.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=42979 and
          http://bugs.debian.org/665420

Reported-by: Romain Francoise <[email protected]> # kernel panic
Reported-by: Chris Holland <[email protected]> # disk detection trouble
Signed-off-by: Matthew Garrett <[email protected]>
Tested-by: Hatem Masmoudi <[email protected]> # Dell Latitude E5520
Tested-by: janek <[email protected]> # pata_jmicron with JMB362/JMB363
[jn: with more symptoms in log message]
Signed-off-by: Jonathan Nieder <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/pci/pcie/aspm.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -500,9 +500,6 @@ static int pcie_aspm_sanity_check(struct
        int pos;
        u32 reg32;
 
-       if (aspm_disabled)
-               return 0;
-
        /*
         * Some functions in a slot might not all be PCIe functions,
         * very strange. Disable ASPM for the whole slot
@@ -511,6 +508,16 @@ static int pcie_aspm_sanity_check(struct
                pos = pci_pcie_cap(child);
                if (!pos)
                        return -EINVAL;
+
+               /*
+                * If ASPM is disabled then we're not going to change
+                * the BIOS state. It's safe to continue even if it's a
+                * pre-1.1 device
+                */
+
+               if (aspm_disabled)
+                       continue;
+
                /*
                 * Disable ASPM for pre-1.1 PCIe device, we follow MS to use
                 * RBER bit to determine if a function is 1.1 version device


Patches currently in stable-queue which might be from [email protected] are

queue-3.3/aspm-fix-pcie-devices-with-non-pcie-children.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to