target/linux/generic/pending-5.10/850-0014-PCI-aardvark-Fix-reading-PCI_EXP_RTSTA_PME-bit-on-em.patch

   1 From 5f354992eeef9a51c67796dc9f7f578d3584baa2 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 05:57:54 +0100
   4 Subject: [PATCH] PCI: aardvark: Fix reading PCI_EXP_RTSTA_PME bit on emulated
   5  bridge
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 The emulated bridge returns incorrect value for PCI_EXP_RTSTA register
  11 during readout in advk_pci_bridge_emul_pcie_conf_read() function: the
  12 correct bit is BIT(16), but we are setting BIT(23), because the code
  13 does
  14   *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16
  15 where
  16   PCIE_MSG_PM_PME_MASK
  17 is
  18   BIT(7).
  19
  20 The code should probably have been something like
  21   *value = (!!(isr0 & PCIE_MSG_PM_PME_MASK)) << 16,
  22 but we are better of using an if() and using the proper macro for this
  23 bit.
  24
  25 Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
  26 Signed-off-by: Pali Rohár <pali@kernel.org>
  27 Signed-off-by: Marek Behún <kabel@kernel.org>
  28 ---
  29  drivers/pci/controller/pci-aardvark.c | 4 +++-
  30  1 file changed, 3 insertions(+), 1 deletion(-)
  31
  32 diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
  33 index 7956b103d3c7..44d9c8c4d258 100644
  34 --- a/drivers/pci/controller/pci-aardvark.c
  35 +++ b/drivers/pci/controller/pci-aardvark.c
  36 @@ -874,7 +874,9 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
  37         case PCI_EXP_RTSTA: {
  38                 u32 isr0 = advk_readl(pcie, PCIE_ISR0_REG);
  39                 u32 msglog = advk_readl(pcie, PCIE_MSG_LOG_REG);
  40 -               *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16 | (msglog >> 16);
  41 +               *value = msglog >> 16;
  42 +               if (isr0 & PCIE_MSG_PM_PME_MASK)
  43 +                       *value |= PCI_EXP_RTSTA_PME;
  44                 return PCI_BRIDGE_EMUL_HANDLED;
  45         }
  46
  47 --
  48 2.34.1
  49