Subject: [PATCH] PCI: iproc: Set all 24 bits of PCI class code

From: Pali Rohár <[email-masked]>
Date: Wed, 5 Jan 2022 10:35:52 +0100

Register 0x43c in its low 24 bits contains PCI class code.

Update code to set all 24 bits of PCI class code and not only upper 16 bits
of PCI class code.

Use a new macro PCI_CLASS_BRIDGE_PCI_NORMAL which represents whole 24 bits
of normal PCI bridge class.

Signed-off-by: Pali Rohár <[email-masked]>

---
Roman helped me with this change and confirmed that class code is stored
really in bits [23:0] of custom register 0x43c (normally class code is
stored in bits [31:8] of pci register 0x08).

This patch depends on patch which adds PCI_CLASS_BRIDGE_PCI_NORMAL macro:
https://lore.kernel.org/linux-pci/[email-masked]/
---
 drivers/pci/controller/pcie-iproc.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index 3df4ab209253..2519201b0e51 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -789,14 +789,13 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie)
 		return -EFAULT;
 	}
 
-	/* force class to PCI_CLASS_BRIDGE_PCI (0x0604) */
+	/* force class to PCI_CLASS_BRIDGE_PCI_NORMAL (0x060400) */
 #define PCI_BRIDGE_CTRL_REG_OFFSET	0x43c
-#define PCI_CLASS_BRIDGE_MASK		0xffff00
-#define PCI_CLASS_BRIDGE_SHIFT		8
+#define PCI_BRIDGE_CTRL_REG_CLASS_MASK	0xffffff
 	iproc_pci_raw_config_read32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
 				    4, &class);
-	class &= ~PCI_CLASS_BRIDGE_MASK;
-	class |= (PCI_CLASS_BRIDGE_PCI << PCI_CLASS_BRIDGE_SHIFT);
+	class &= ~PCI_BRIDGE_CTRL_REG_CLASS_MASK;
+	class |= PCI_CLASS_BRIDGE_PCI_NORMAL;
 	iproc_pci_raw_config_write32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
 				     4, class);
 
-- 
2.20.1

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