target/linux/generic/pending-5.15/850-0002-PCI-aardvark-Fix-reading-MSI-interrupt-number.patch

   1 From a29a7d01cd778854e08108461cba321a63d98871 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
   3 Date: Fri, 2 Jul 2021 16:39:47 +0200
   4 Subject: [PATCH] PCI: aardvark: Fix reading MSI interrupt number
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 In advk_pcie_handle_msi() the authors expect that when bit i in the W1C
  10 register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is
  11 updated to contain the MSI number corresponding to index i.
  12
  13 Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG
  14 always contains the number of the last received MSI, overall.
  15
  16 Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
  17 number. Since Aardvark already forbids more than 32 interrupts and uses
  18 own allocated hwirq numbers, the msi_idx already corresponds to the
  19 received MSI number.
  20
  21 Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
  22 Signed-off-by: Pali Rohár <pali@kernel.org>
  23 Signed-off-by: Marek Behún <kabel@kernel.org>
  24 ---
  25  drivers/pci/controller/pci-aardvark.c | 13 ++++++-------
  26  1 file changed, 6 insertions(+), 7 deletions(-)
  27
  28 --- a/drivers/pci/controller/pci-aardvark.c
  29 +++ b/drivers/pci/controller/pci-aardvark.c
  30 @@ -1386,7 +1386,7 @@ static void advk_pcie_remove_irq_domain(
  31  static void advk_pcie_handle_msi(struct advk_pcie *pcie)
  32  {
  33         u32 msi_val, msi_mask, msi_status, msi_idx;
  34 -       u16 msi_data;
  35 +       int virq;
  36
  37         msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
  38         msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG);
  39 @@ -1396,13 +1396,12 @@ static void advk_pcie_handle_msi(struct
  40                 if (!(BIT(msi_idx) & msi_status))
  41                         continue;
  42
  43 -               /*
  44 -                * msi_idx contains bits [4:0] of the msi_data and msi_data
  45 -                * contains 16bit MSI interrupt number
  46 -                */
  47                 advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG);
  48 -               msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK;
  49 -               generic_handle_irq(msi_data);
  50 +               virq = irq_find_mapping(pcie->msi_inner_domain, msi_idx);
  51 +               if (virq)
  52 +                       generic_handle_irq(virq);
  53 +               else
  54 +                       dev_err_ratelimited(&pcie->pdev->dev, "unexpected MSI 0x%02x\n", msi_idx);
  55         }
  56
  57         advk_writel(pcie, PCIE_ISR0_MSI_INT_PENDING,