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Message-id: <alpine.LFD.2.00.1009242122390.8641@localhost.localdomain>
Date: Fri, 24 Sep 2010 21:26:31 -0400 (EDT)
From: Len Brown <lenb@...nel.org>
To: Linux Power Management List <linux-pm@...ts.osdl.org>
Cc: linux-pci@...r.kernel.org,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH] intel_idle: PCI quirk to prevent Lenovo Ideapad s10-3 boot hang
From: Len Brown <len.brown@...el.com>
When the Lenovo Ideapad S10-3 is booted with HT enabled,
it hits a boot hang in the intel_idle driver.
This occurs when entering ATM-C4 for the first time,
unless BM_STS is first cleared.
acpi_idle doesn't see this because it first checks
and clears BM_STS, but it would hit the same hang
if that check were disabled.
http://bugs.meego.com/show_bug.cgi?id=7093
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/634702
Signed-off-by: Len Brown <len.brown@...el.com>
---
drivers/pci/quirks.c | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 197e38f..a8dbf2e 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -155,6 +155,26 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC, PCI_DEVICE_ID_NEC_CBUS_2, quirk_isa_d
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC, PCI_DEVICE_ID_NEC_CBUS_3, quirk_isa_dma_hangs);
/*
+ * Intel NM10 "TigerPoint" LPC PM1a_STS.BM_STS must be clear
+ * for some HT machines to use C4 w/o hanging.
+ */
+static void __devinit quirk_tigerpoint_bm_sts(struct pci_dev *dev)
+{
+ u32 pmbase;
+ u16 pm1a;
+
+ pci_read_config_dword(dev, 0x40, &pmbase);
+ pmbase = pmbase & 0xff80;
+ pm1a = inw(pmbase);
+
+ if (pm1a & 0x10) {
+ dev_info(&dev->dev, FW_BUG "TigerPoint LPC.BM_STS cleared\n");
+ outw(0x10, pmbase);
+ }
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TGP_LPC, quirk_tigerpoint_bm_sts);
+
+/*
* Chipsets where PCI->PCI transfers vanish or hang
*/
static void __devinit quirk_nopcipci(struct pci_dev *dev)
--
1.7.3
--
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