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From: Konrad Dybcio <konrad.dybcio@linaro.org>
To: "Manivannan Sadhasivam" <mani@kernel.org>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	"Stanimir Varbanov" <svarbanov@mm-sol.com>,
	"Andrew Murray" <amurray@thegoodpenguin.co.uk>,
	"Vinod Koul" <vkoul@kernel.org>
Cc: Marijn Suijten <marijn.suijten@somainline.org>,
	 linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org,
	 linux-kernel@vger.kernel.org,
	Konrad Dybcio <konrad.dybcio@linaro.org>
Subject: [PATCH 3/4] PCI: qcom: Read back PARF_LTSSM register
Date: Wed, 27 Dec 2023 23:17:21 +0100	[thread overview]
Message-ID: <20231227-topic-8280_pcie-v1-3-095491baf9e4@linaro.org> (raw)
In-Reply-To: <20231227-topic-8280_pcie-v1-0-095491baf9e4@linaro.org>

To ensure write completion, read the PARF_LTSSM register after setting
the LTSSM enable bit before polling for "link up".

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index a02dc197c495..3d77269e70da 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -540,6 +540,7 @@ static void qcom_pcie_2_3_2_ltssm_enable(struct qcom_pcie *pcie)
 	val = readl(pcie->parf + PARF_LTSSM);
 	val |= LTSSM_EN;
 	writel(val, pcie->parf + PARF_LTSSM);
+	readl(pcie->parf + PARF_LTSSM);
 }
 
 static int qcom_pcie_get_resources_2_3_2(struct qcom_pcie *pcie)

-- 
2.43.0


  parent reply	other threads:[~2023-12-27 22:17 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-27 22:17 [PATCH 0/4] Qualcomm PCIe RC shutdown & reinit Konrad Dybcio
2023-12-27 22:17 ` [PATCH 1/4] PCI: qcom: Reshuffle reset logic in 2_7_0 .init Konrad Dybcio
2023-12-29 14:04   ` Johan Hovold
2023-12-29 15:01     ` Konrad Dybcio
2023-12-29 15:29       ` Johan Hovold
2023-12-30  1:16         ` Konrad Dybcio
2024-01-01 17:31           ` Manivannan Sadhasivam
2024-01-02 10:17           ` Johan Hovold
2024-01-02 17:03             ` Konrad Dybcio
2024-01-03 10:40               ` Johan Hovold
2024-01-03 12:11                 ` Konrad Dybcio
2023-12-29 15:46     ` Bjorn Helgaas
2023-12-30 22:11       ` Konrad Dybcio
2023-12-27 22:17 ` [PATCH 2/4] PCI: qcom: Cache last icc bandwidth Konrad Dybcio
2023-12-27 22:17 ` Konrad Dybcio [this message]
2024-01-02 17:05   ` [PATCH 3/4] PCI: qcom: Read back PARF_LTSSM register Manivannan Sadhasivam
2023-12-27 22:17 ` [PATCH 4/4] PCI: qcom: Implement RC shutdown/power up Konrad Dybcio
2023-12-28 15:12   ` kernel test robot
2023-12-29  3:42   ` kernel test robot
2024-01-02 17:07   ` Manivannan Sadhasivam

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