target/linux/generic/pending-5.10/850-0016-PCI-aardvark-Add-support-for-PME-interrupts.patch

   1 From 7acd8ef92e8789e10b5d736d73cea3b625087f26 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
   3 Date: Wed, 8 Dec 2021 06:07:44 +0100
   4 Subject: [PATCH] PCI: aardvark: Add support for PME interrupts
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Currently enabling PCI_EXP_RTSTA_PME bit in PCI_EXP_RTCTL register does
  10 nothing. This is because PCIe PME driver expects to receive PCIe interrupt
  11 defined in PCI_EXP_FLAGS_IRQ register, but aardvark hardware does not
  12 trigger PCIe INTx/MSI interrupt for PME event, rather it triggers custom
  13 aardvark interrupt which this driver is not processing yet.
  14
  15 Fix this issue by handling PME interrupt in advk_pcie_handle_int() and
  16 chaining it to PCIe interrupt 0 with generic_handle_domain_irq() (since
  17 aardvark sets PCI_EXP_FLAGS_IRQ to zero). With this change PCIe PME driver
  18 finally starts receiving PME interrupt.
  19
  20 Signed-off-by: Pali Rohár <pali@kernel.org>
  21 Signed-off-by: Marek Behún <kabel@kernel.org>
  22 ---
  23  drivers/pci/controller/pci-aardvark.c | 13 +++++++++++++
  24  1 file changed, 13 insertions(+)
  25
  26 --- a/drivers/pci/controller/pci-aardvark.c
  27 +++ b/drivers/pci/controller/pci-aardvark.c
  28 @@ -1491,6 +1491,19 @@ static void advk_pcie_handle_int(struct
  29         isr1_mask = advk_readl(pcie, PCIE_ISR1_MASK_REG);
  30         isr1_status = isr1_val & ((~isr1_mask) & PCIE_ISR1_ALL_MASK);
  31
  32 +       /* Process PME interrupt */
  33 +       if (isr0_status & PCIE_MSG_PM_PME_MASK) {
  34 +               /*
  35 +                * Do not clear PME interrupt bit in ISR0, it is cleared by IRQ
  36 +                * receiver by writing to the PCI_EXP_RTSTA register of emulated
  37 +                * root bridge. Aardvark HW returns zero for PCI_EXP_FLAGS_IRQ,
  38 +                * so use PCIe interrupt 0.
  39 +                */
  40 +               virq = irq_find_mapping(pcie->irq_domain, 0);
  41 +               if (generic_handle_irq(virq) == -EINVAL)
  42 +                       dev_err_ratelimited(&pcie->pdev->dev, "unhandled PME IRQ\n");
  43 +       }
  44 +
  45         /* Process ERR interrupt */
  46         if (isr0_status & PCIE_ISR0_ERR_MASK) {
  47                 advk_writel(pcie, PCIE_ISR0_ERR_MASK, PCIE_ISR0_REG);