We currently enable clocks BEFORE we write to PARF_PHY_CTRL reg to enable clocks and resets. This case the driver to never set to a ready state with the error 'Phy link never came up'.
This in fact is caused by the phy clock getting enabled before setting the required bits in the PARF regs.
A workaround for this was set but with this new discovery we can drop the workaround and use a proper solution to the problem by just enabling the clock only AFTER the PARF_PHY_CTRL bit is set.
This correctly setup the pcie line and makes it usable even when a bootloader leave the pcie line to a underfined state.
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Christian Marangi ansuelsmth@gmail.com --- drivers/pci/controller/dwc/pcie-qcom.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 2ea13750b492..da13a66ced14 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -337,8 +337,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) reset_control_assert(res->ext_reset); reset_control_assert(res->phy_reset);
- writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL); - ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies); if (ret < 0) { dev_err(dev, "cannot enable regulators\n"); @@ -381,15 +379,15 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) goto err_deassert_axi; }
- ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks); - if (ret) - goto err_clks; - /* enable PCIe clocks and resets */ val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL); val &= ~BIT(0); writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+ ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks); + if (ret) + goto err_clks; + if (of_device_is_compatible(node, "qcom,pcie-ipq8064") || of_device_is_compatible(node, "qcom,pcie-ipq8064-v2")) { writel(PCS_DEEMPH_TX_DEEMPH_GEN1(24) |
On Sat, Jul 09, 2022 at 12:27:43AM +0200, Christian Marangi wrote:
We currently enable clocks BEFORE we write to PARF_PHY_CTRL reg to enable clocks and resets. This case the driver to never set to a ready state with the error 'Phy link never came up'.
This in fact is caused by the phy clock getting enabled before setting the required bits in the PARF regs.
A workaround for this was set but with this new discovery we can drop the workaround and use a proper solution to the problem by just enabling the clock only AFTER the PARF_PHY_CTRL bit is set.
This correctly setup the pcie line and makes it usable even when a bootloader leave the pcie line to a underfined state.
Is "pcie" here a signal name? Maybe this refers to the "PCIe link"?
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Christian Marangi ansuelsmth@gmail.com
Thanks, I put this on https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git, pci/ctrl/qcom-pending branch (head 47b4ec9d2e60).
Can you take a look and make sure I didn't mess up the conflict resolution with the rest of the series?
drivers/pci/controller/dwc/pcie-qcom.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 2ea13750b492..da13a66ced14 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -337,8 +337,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) reset_control_assert(res->ext_reset); reset_control_assert(res->phy_reset);
- writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
- ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies); if (ret < 0) { dev_err(dev, "cannot enable regulators\n");
@@ -381,15 +379,15 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) goto err_deassert_axi; }
- ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
- if (ret)
goto err_clks;- /* enable PCIe clocks and resets */ val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL); val &= ~BIT(0); writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
- ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
- if (ret)
goto err_clks;- if (of_device_is_compatible(node, "qcom,pcie-ipq8064") || of_device_is_compatible(node, "qcom,pcie-ipq8064-v2")) { writel(PCS_DEEMPH_TX_DEEMPH_GEN1(24) |
-- 2.36.1
On Fri, Jul 08, 2022 at 06:01:55PM -0500, Bjorn Helgaas wrote:
On Sat, Jul 09, 2022 at 12:27:43AM +0200, Christian Marangi wrote:
We currently enable clocks BEFORE we write to PARF_PHY_CTRL reg to enable clocks and resets. This case the driver to never set to a ready state with the error 'Phy link never came up'.
This in fact is caused by the phy clock getting enabled before setting the required bits in the PARF regs.
A workaround for this was set but with this new discovery we can drop the workaround and use a proper solution to the problem by just enabling the clock only AFTER the PARF_PHY_CTRL bit is set.
This correctly setup the pcie line and makes it usable even when a bootloader leave the pcie line to a underfined state.
Is "pcie" here a signal name? Maybe this refers to the "PCIe link"?
Hi, no i was referring to PCIe link. Fell free to fix it if it's not a problem (or if you want i can just resend)
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Christian Marangi ansuelsmth@gmail.com
Thanks, I put this on https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git, pci/ctrl/qcom-pending branch (head 47b4ec9d2e60).
Can you take a look and make sure I didn't mess up the conflict resolution with the rest of the series?
Think something went wrong in the rebase as the patch fixup is reverted.
11946f8b6e77a6794c111aafef7772e9967d9a54 is still wrong.
clk_bulk_prepare_enable must be after writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL); so in the post init.
drivers/pci/controller/dwc/pcie-qcom.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 2ea13750b492..da13a66ced14 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -337,8 +337,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) reset_control_assert(res->ext_reset); reset_control_assert(res->phy_reset);
- writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
- ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies); if (ret < 0) { dev_err(dev, "cannot enable regulators\n");
@@ -381,15 +379,15 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) goto err_deassert_axi; }
- ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
- if (ret)
goto err_clks;- /* enable PCIe clocks and resets */ val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL); val &= ~BIT(0); writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
- ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
- if (ret)
goto err_clks;- if (of_device_is_compatible(node, "qcom,pcie-ipq8064") || of_device_is_compatible(node, "qcom,pcie-ipq8064-v2")) { writel(PCS_DEEMPH_TX_DEEMPH_GEN1(24) |
-- 2.36.1
linux-stable-mirror@lists.linaro.org
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Bjorn Helgaas -
Christian Marangi