[PATCH 5.10 125/238] PCI/DPC: Print all TLP Prefixes, not just the first

[Sasha Levin]

From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

[ Upstream commit 6568d82512b0a64809acff3d7a747362fa4288c8 ]

The TLP Prefix Log Register consists of multiple DWORDs (PCIe r6.1 sec
7.9.14.13) but the loop in dpc_process_rp_pio_error() keeps reading from
the first DWORD, so we print only the first PIO TLP Prefix (duplicated
several times), and we never print the second, third, etc., Prefixes.

Add the iteration count based offset calculation into the config read.

Fixes: f20c4ea49ec4 ("PCI/DPC: Add eDPC support")
Link: https://lore.kernel.org/r/20240118110815.3867-1-ilpo.jarvinen@xxxxxxxxxxxxxxx
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
[bhelgaas: add user-visible details to commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/pcie/dpc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index f21d64ae4ffcc..cf0d4ba2e157a 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -231,7 +231,7 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 
 	for (i = 0; i < pdev->dpc_rp_log_size - 5; i++) {
 		pci_read_config_dword(pdev,
-			cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix);
+			cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG + i * 4, &prefix);
 		pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix);
 	}
  clear_status:
-- 
2.43.0