Am Samstag, den 28.06.2014, 22:37 +0800 schrieb Shawn Guo:
> On Thu, Jun 26, 2014 at 10:43:49AM +0200, Lucas Stach wrote:
> > Am Mittwoch, den 25.06.2014, 20:53 +0800 schrieb Shawn Guo:
> > > On Wed, Jun 25, 2014 at 12:50:52PM +0200, Lucas Stach wrote:
> > > > Am Mittwoch, den 25.06.2014, 07:50 -0300 schrieb Fabio Estevam:
> > > > > On Wed, Jun 25, 2014 at 3:22 AM, Shawn Guo <shawn.guo@xxxxxxxxxx> wrote:
> > > > >
> > > > > > Please test against v3.16-rc1 or -rc2. The breakage on linux-next
> > > > > > should be another issue.
> > > > >
> > > > > Yes, I see it now. Tested on -rc2 and suspend/resume works with PCI
> > > > > driver removed.
> > > >
> > > > Can you please send me a dmesg from a working boot?
> > >
> > > What do you mean by "working boot"? Boot is always working. What fails
> > > is system resuming.
> > >
> > > Shawn
> > >
> > Oops, what I meant is a dmesg after a working resume (from kernel 3.15).
> > I can see how failing to resume from L2 can cause the hang and we should
> > really implement the PHY PD toggling in the pcie driver, but I would
> > like to understand why you don't hit this on 3.15.
>
> Sorry, Lucas. I just noticed that in my 3.15 testing PCIe is not
> enabled in device tree at all. So the issue should have already been
> there before your changes to PCIe driver.
>
Hi Shawn,
can you please test the attached patch on top of 3.16-rc* to see if it
helps? If it works for you I would like to try and get this into 3.16 as
a bugfix.
Regards,
Lucas
--------------------------->8-----------------------------
>From f3bfdc9c19249188fa153b1568c3129cd31af4f5 Mon Sep 17 00:00:00 2001
From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Date: Mon, 30 Jun 2014 15:33:04 +0200
Subject: [PATCH] PCI: imx6: add workaround for errata ERR005723
Fixes system hang after resume from suspend to mem.
Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
---
drivers/pci/host/pci-imx6.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index a568efaa331c..5c58a3ee5dbf 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -589,6 +589,38 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
return 0;
}
+#ifdef CONFIG_PM_SLEEP
+static int imx6_pcie_suspend(struct device *dev)
+{
+ struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+ IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
+
+ return 0;
+}
+
+static int imx6_pcie_resume(struct device *dev)
+{
+ struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+
+ /*
+ * This is a workaround for
+ * ERR005723: PCIe does not support L2 power down
+ * Toggling the PHY PD bit around system L2 state switching seems to be
+ * enough to wake the PCIe logic after a power down.
+ */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+ IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(imx6_pcie_pm_ops,
+ imx6_pcie_suspend,
+ imx6_pcie_resume);
+
static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", },
{},
@@ -600,6 +632,7 @@ static struct platform_driver imx6_pcie_driver = {
.name = "imx6q-pcie",
.owner = THIS_MODULE,
.of_match_table = imx6_pcie_of_match,
+ .pm = &imx6_pcie_pm_ops,
},
};
--
2.0.0
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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