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From: Jiwei Sun <sjiwei@163.com>
To: macro@orcam.me.uk, ilpo.jarvinen@linux.intel.com, bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	helgaas@kernel.org, lukas@wunner.de, ahuang12@lenovo.com,
	sunjw10@lenovo.com, jiwei.sun.bj@qq.com, sunjw10@outlook.com
Subject: [PATCH v2 2/2] PCI: reread the Link Control 2 Register before using
Date: Wed, 15 Jan 2025 21:41:54 +0800	[thread overview]
Message-ID: <20250115134154.9220-3-sjiwei@163.com> (raw)
In-Reply-To: <20250115134154.9220-1-sjiwei@163.com>

From: Jiwei Sun <sunjw10@lenovo.com>

Since commit de9a6c8d5dbf ("PCI/bwctrl: Add pcie_set_target_speed() to set
PCIe Link Speed"), the local variable "lnkctl2" is not changed after
reading from PCI_EXP_LNKCTL2 in the pcie_failed_link_retrain(). It might
cause that the removing 2.5GT/s downstream link speed restriction codes
are not executed.

Reread the Link Control 2 Register before using.

Fixes: de9a6c8d5dbf ("PCI/bwctrl: Add pcie_set_target_speed() to set PCIe Link Speed")
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiwei Sun <sunjw10@lenovo.com>
---
 drivers/pci/quirks.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 76f4df75b08a..02d2e16672a8 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -123,6 +123,7 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
 			return ret;
 		}
 
+		pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
 		pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
 	}
 
-- 
2.34.1


  parent reply	other threads:[~2025-01-15 13:42 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-15 13:41 [PATCH v2 0/2] PCI: Fix the wrong reading of register fields Jiwei Sun
2025-01-15 13:41 ` [PATCH v2 1/2] " Jiwei Sun
2025-01-16 13:52   ` Ilpo Järvinen
2025-01-15 13:41 ` Jiwei Sun [this message]
2025-01-16 14:12   ` [PATCH v2 2/2] PCI: reread the Link Control 2 Register before using Ilpo Järvinen
2025-01-16 15:00     ` Maciej W. Rozycki
2025-01-17 13:53     ` Jiwei Sun
2025-01-18  1:03       ` Maciej W. Rozycki
2025-01-20 14:19         ` Jiwei
2025-01-20 15:05           ` Maciej W. Rozycki
2025-01-20 15:20             ` Jiwei

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