92 lines
3.2 KiB
Diff
92 lines
3.2 KiB
Diff
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From b74bab6186131eea09459eedf5d737645a3559c9 Mon Sep 17 00:00:00 2001
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From: Abhishek Sahu <absahu@codeaurora.org>
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Date: Thu, 22 Dec 2016 11:18:45 +0530
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Subject: pcie: qcom: Fixed pcie_phy_clk branch issue
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Following backtraces are observed in PCIe deinit operation.
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Hardware name: Qualcomm (Flattened Device Tree)
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(unwind_backtrace) from [] (show_stack+0x10/0x14)
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(show_stack) from [] (dump_stack+0x84/0x98)
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(dump_stack) from [] (warn_slowpath_common+0x9c/0xb8)
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(warn_slowpath_common) from [] (warn_slowpath_fmt+0x30/0x40)
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(warn_slowpath_fmt) from [] (clk_branch_wait+0x114/0x120)
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(clk_branch_wait) from [] (clk_core_disable+0xd0/0x1f4)
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(clk_core_disable) from [] (clk_disable+0x24/0x30)
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(clk_disable) from [] (qcom_pcie_deinit_v0+0x6c/0xb8)
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(qcom_pcie_deinit_v0) from [] (qcom_pcie_host_init+0xe0/0xe8)
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(qcom_pcie_host_init) from [] (dw_pcie_host_init+0x3b0/0x538)
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(dw_pcie_host_init) from [] (qcom_pcie_probe+0x20c/0x2e4)
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pcie_phy_clk is generated for PCIe controller itself and the
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GCC controls its branch operation. This error is coming since
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the assert operations turn off the parent clock before branch
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clock. Now this patch moves clk_disable_unprepare before assert
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operations.
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Similarly, during probe function, the clock branch operation
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should be done after dessert operation. Currently, it does not
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generate any error since bootloader enables the pcie_phy_clk
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but the same error is coming during probe, if bootloader
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disables pcie_phy_clk.
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Change-Id: Ib29c154d10eb64363d9cc982ce5fd8107af5627d
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Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
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---
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drivers/pci/host/pcie-qcom.c | 16 +++++++---------
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1 file changed, 7 insertions(+), 9 deletions(-)
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--- a/drivers/pci/dwc/pcie-qcom.c
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+++ b/drivers/pci/dwc/pcie-qcom.c
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@@ -407,6 +407,7 @@ static void qcom_pcie_deinit_2_1_0(struc
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{
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struct qcom_pcie_resources_2_1_0 *res = &pcie->res.v2_1_0;
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+ clk_disable_unprepare(res->phy_clk);
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reset_control_assert(res->pci_reset);
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reset_control_assert(res->axi_reset);
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reset_control_assert(res->ahb_reset);
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@@ -415,7 +416,6 @@ static void qcom_pcie_deinit_2_1_0(struc
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reset_control_assert(res->ext_reset);
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clk_disable_unprepare(res->iface_clk);
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clk_disable_unprepare(res->core_clk);
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- clk_disable_unprepare(res->phy_clk);
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clk_disable_unprepare(res->aux_clk);
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clk_disable_unprepare(res->ref_clk);
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regulator_disable(res->vdda);
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@@ -472,12 +472,6 @@ static int qcom_pcie_init_2_1_0(struct q
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goto err_clk_core;
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}
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- ret = clk_prepare_enable(res->phy_clk);
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- if (ret) {
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- dev_err(dev, "cannot prepare/enable phy clock\n");
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- goto err_clk_phy;
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- }
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-
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ret = clk_prepare_enable(res->aux_clk);
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if (ret) {
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dev_err(dev, "cannot prepare/enable aux clock\n");
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@@ -541,6 +535,12 @@ static int qcom_pcie_init_2_1_0(struct q
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return ret;
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}
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+ ret = clk_prepare_enable(res->phy_clk);
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+ if (ret) {
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+ dev_err(dev, "cannot prepare/enable phy clock\n");
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+ goto err_deassert_ahb;
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+ }
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+
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/* wait for clock acquisition */
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usleep_range(1000, 1500);
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if (pcie->force_gen1) {
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@@ -566,8 +566,6 @@ err_deassert_ahb:
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err_clk_ref:
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clk_disable_unprepare(res->aux_clk);
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err_clk_aux:
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- clk_disable_unprepare(res->phy_clk);
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-err_clk_phy:
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clk_disable_unprepare(res->core_clk);
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err_clk_core:
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clk_disable_unprepare(res->iface_clk);
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