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authorRafael J. Wysocki <rjw@sisk.pl>2010-02-17 23:40:07 +0100
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-02-22 16:20:39 -0800
commitc39fae1416d59fd565606793f090cebe3720d50d (patch)
treef53b3dc3202706c328c2306f168058ec2e9ae859 /Documentation
parentc7f486567c1d0acd2e4166c47069835b9f75e77b (diff)
downloadlinux-c39fae1416d59fd565606793f090cebe3720d50d.tar.bz2
PCI PM: Make it possible to force using INTx for PCIe PME signaling
Apparently, some machines may have problems with PCI run-time power management if MSIs are used for the native PCIe PME signaling. In particular, on the MSI Wind U-100 PCIe PME interrupts are not generated by a PCIe root port after a resume from suspend to RAM, if the system wake-up was triggered by a PME from the device attached to this port. [It doesn't help to free the interrupt on suspend and request it back on resume, even if that is done along with disabling the MSI and re-enabling it, respectively.] However, if INTx interrupts are used for this purpose on the same machine, everything works just fine. For this reason, add a kernel command line switch allowing one to request that MSIs be not used for the native PCIe PME signaling, introduce a DMI table allowing us to blacklist machines that need this switch to be set by default and put the MSI Wind U-100 into this table. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kernel-parameters.txt2
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 747a2c8f62f3..516225a864f9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2003,6 +2003,8 @@ and is between 256 and 4096 characters. It is defined in the file
force Use native PCIe PME signaling even if the BIOS refuses
to allow the kernel to control the relevant PCIe config
registers.
+ nomsi Do not use MSI for native PCIe PME signaling (this makes
+ all PCIe root ports use INTx for everything).
pcmv= [HW,PCMCIA] BadgePAD 4