target/linux/generic/backport-5.10/822-v5.13-advertise-lack-of-built-in-msi-handling.patch

   1 From 645e9c38383d7fcde2784ee537fa18ec9bed54d9 Mon Sep 17 00:00:00 2001
   2 From: Thomas Gleixner <tglx@linutronix.de>
   3 Date: Tue, 30 Mar 2021 16:11:43 +0100
   4 Subject: PCI: mediatek: Advertise lack of built-in MSI handling
   5
   6 Some Mediatek host bridges cannot handle MSIs, which is sad.
   7 This also results in an ugly warning at device probe time,
   8 as the core PCI code wasn't told that MSIs were not available.
   9
  10 Advertise this fact to the rest of the core PCI code by
  11 using the 'msi_domain' attribute, which still opens the possibility
  12 for another block to provide the MSI functionnality.
  13
  14 [maz: commit message, switched over to msi_domain attribute]
  15
  16 Link: https://lore.kernel.org/r/20210330151145.997953-13-maz@kernel.org
  17 Reported-by: Frank Wunderlich <frank-w@public-files.de>
  18 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  19 Signed-off-by: Marc Zyngier <maz@kernel.org>
  20 Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
  21 Acked-by: Bjorn Helgaas <bhelgaas@google.com>
  22 ---
  23  drivers/pci/controller/pcie-mediatek.c | 4 ++++
  24  1 file changed, 4 insertions(+)
  25
  26 --- a/drivers/pci/controller/pcie-mediatek.c
  27 +++ b/drivers/pci/controller/pcie-mediatek.c
  28 @@ -143,6 +143,7 @@ struct mtk_pcie_port;
  29   * struct mtk_pcie_soc - differentiate between host generations
  30   * @need_fix_class_id: whether this host's class ID needed to be fixed or not
  31   * @need_fix_device_id: whether this host's device ID needed to be fixed or not
  32 + * @no_msi: Bridge has no MSI support, and relies on an external block
  33   * @device_id: device ID which this host need to be fixed
  34   * @ops: pointer to configuration access functions
  35   * @startup: pointer to controller setting functions
  36 @@ -151,6 +152,7 @@ struct mtk_pcie_port;
  37  struct mtk_pcie_soc {
  38         bool need_fix_class_id;
  39         bool need_fix_device_id;
  40 +       bool no_msi;
  41         unsigned int device_id;
  42         struct pci_ops *ops;
  43         int (*startup)(struct mtk_pcie_port *port);
  44 @@ -1087,6 +1089,7 @@ static int mtk_pcie_probe(struct platfor
  45
  46         host->ops = pcie->soc->ops;
  47         host->sysdata = pcie;
  48 +       host->msi_domain = pcie->soc->no_msi;
  49
  50         err = pci_host_probe(host);
  51         if (err)
  52 @@ -1176,6 +1179,7 @@ static const struct dev_pm_ops mtk_pcie_
  53  };
  54
  55  static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
  56 +       .no_msi = true,
  57         .ops = &mtk_pcie_ops,
  58         .startup = mtk_pcie_startup_port,
  59  };