On 9/10/2020 11:50 AM, Rob Herring wrote:
On Thu, Sep 10, 2020 at 10:42 AM Jim Quinlan <james.quin...@broadcom.com> wrote:

On Thu, Sep 10, 2020 at 11:56 AM Rob Herring <r...@kernel.org> wrote:

On Mon, Aug 24, 2020 at 03:30:17PM -0400, Jim Quinlan wrote:
From: Jim Quinlan <jquin...@broadcom.com>

Broadcom Set-top (BrcmSTB) boards typically support S2, S3, and S5 suspend
and resume.  Now the PCIe driver may do so as well.

Signed-off-by: Jim Quinlan <jquin...@broadcom.com>
Acked-by: Florian Fainelli <f.faine...@gmail.com>
---
  drivers/pci/controller/pcie-brcmstb.c | 47 +++++++++++++++++++++++++++
  1 file changed, 47 insertions(+)

diff --git a/drivers/pci/controller/pcie-brcmstb.c 
b/drivers/pci/controller/pcie-brcmstb.c
index c2b3d2946a36..3d588ab7a6dd 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -978,6 +978,47 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
       brcm_pcie_bridge_sw_init_set(pcie, 1);
  }

+static int brcm_pcie_suspend(struct device *dev)
+{
+     struct brcm_pcie *pcie = dev_get_drvdata(dev);
+
+     brcm_pcie_turn_off(pcie);
+     clk_disable_unprepare(pcie->clk);
+
+     return 0;
+}
+
+static int brcm_pcie_resume(struct device *dev)
+{
+     struct brcm_pcie *pcie = dev_get_drvdata(dev);
+     void __iomem *base;
+     u32 tmp;
+     int ret;
+
+     base = pcie->base;
+     clk_prepare_enable(pcie->clk);
+
+     /* Take bridge out of reset so we can access the SERDES reg */
+     brcm_pcie_bridge_sw_init_set(pcie, 0);
+
+     /* SERDES_IDDQ = 0 */
+     tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+     u32p_replace_bits(&tmp, 0, 
PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
+     writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+
+     /* wait for serdes to be stable */
+     udelay(100);

Really needs to be a spinloop?

+
+     ret = brcm_pcie_setup(pcie);
+     if (ret)
+             return ret;
+
+     if (pcie->msi)
+             brcm_msi_set_regs(pcie->msi);
+
+     return 0;
+}
+
  static void __brcm_pcie_remove(struct brcm_pcie *pcie)
  {
       brcm_msi_remove(pcie);
@@ -1087,12 +1128,18 @@ static int brcm_pcie_probe(struct platform_device *pdev)

  MODULE_DEVICE_TABLE(of, brcm_pcie_match);

+static const struct dev_pm_ops brcm_pcie_pm_ops = {
+     .suspend_noirq = brcm_pcie_suspend,
+     .resume_noirq = brcm_pcie_resume,

Why do you need interrupts disabled? There's 39 cases of .suspend_noirq
and 1352 of .suspend in the tree.

I will test switching this to  suspend_late/resume_early.

Why not just the 'regular' flavor suspend/resume?

We must have inherited this from when the driver was not a platform_device back in our 3.14 downstream kernel and we used syscore_ops to do the system suspend/resume.

Later on, we sort of mechanically made those _noirq() to preserve the semantics of syscore_ops, but in hindsight it should not be necessary, the regular suspsend/resume should work and the device driver model ordering between parent/child should take care of the bridge being suspended last within the PCI bus type that is.
--
Florian

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