Subject: [PATCH v2 14/23] PCI: aardvark: Fix reading PCI_EXP_RTSTA_PME bit on emulated bridge

From: Marek Behún <[email-masked]>
Date: Mon, 10 Jan 2022 02:50:09 +0100

From: Pali Rohár <[email-masked]>

The emulated bridge returns incorrect value for PCI_EXP_RTSTA register
during readout in advk_pci_bridge_emul_pcie_conf_read() function: the
correct bit is BIT(16), but we are setting BIT(23), because the code
does
  *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16
where
  PCIE_MSG_PM_PME_MASK
is
  BIT(7).

The code should probably have been something like
  *value = (!!(isr0 & PCIE_MSG_PM_PME_MASK)) << 16,
but we are better of using an if() and using the proper macro for this
bit.

Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <[email-masked]>
Signed-off-by: Marek Behún <[email-masked]>
---
 drivers/pci/controller/pci-aardvark.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 6fc6c3199954..8706a5f58eb5 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -876,7 +876,9 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
 	case PCI_EXP_RTSTA: {
 		u32 isr0 = advk_readl(pcie, PCIE_ISR0_REG);
 		u32 msglog = advk_readl(pcie, PCIE_MSG_LOG_REG);
-		*value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16 | (msglog >> 16);
+		*value = msglog >> 16;
+		if (isr0 & PCIE_MSG_PM_PME_MASK)
+			*value |= PCI_EXP_RTSTA_PME;
 		return PCI_BRIDGE_EMUL_HANDLED;
 	}
 
-- 
2.34.1

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