[PATCH v4 01/16] phy: qcom-qmp: Fix phy pipe clock gating

[Manu Gautam <mgautam@codeaurora.org>]

From: Vivek Gautam <vivek.gautam@codeaurora.org>

Pipe clock comes out of the phy and is available as long as
the phy is turned on. Clock controller fails to gate this
clock after the phy is turned off and generates a warning.

/ # [   33.048561] gcc_usb3_phy_pipe_clk status stuck at 'on'
[   33.048585] ------------[ cut here ]------------
[   33.052621] WARNING: CPU: 1 PID: 18 at ../drivers/clk/qcom/clk-branch.c:97 clk_branch_wait+0xf0/0x108
[   33.057384] Modules linked in:
[   33.066497] CPU: 1 PID: 18 Comm: kworker/1:0 Tainted: G        W       4.12.0-rc7-00024-gfe926e34c36d-dirty #96
[   33.069451] Hardware name: Qualcomm Technologies, Inc. DB820c (DT)
...
[   33.278565] [<ffff00000849b27c>] clk_branch_wait+0xf0/0x108
[   33.286375] [<ffff00000849b2f4>] clk_branch2_disable+0x28/0x34
[   33.291761] [<ffff0000084868dc>] clk_core_disable+0x5c/0x88
[   33.297660] [<ffff000008487d68>] clk_core_disable_lock+0x20/0x34
[   33.303129] [<ffff000008487d98>] clk_disable+0x1c/0x24
[   33.309384] [<ffff0000083ccd78>] qcom_qmp_phy_poweroff+0x20/0x48
[   33.314328] [<ffff0000083c53f4>] phy_power_off+0x80/0xdc
[   33.320492] [<ffff00000875c950>] dwc3_core_exit+0x94/0xa0
[   33.325784] [<ffff00000875c9ac>] dwc3_suspend_common+0x50/0x60
[   33.331080] [<ffff00000875ca04>] dwc3_runtime_suspend+0x48/0x6c
[   33.336810] [<ffff0000085b82f4>] pm_generic_runtime_suspend+0x28/0x38
[   33.342627] [<ffff0000085bace0>] __rpm_callback+0x150/0x254
[   33.349222] [<ffff0000085bae08>] rpm_callback+0x24/0x78
[   33.354604] [<ffff0000085b9fd8>] rpm_suspend+0xe0/0x4e4
[   33.359813] [<ffff0000085bb784>] pm_runtime_work+0xdc/0xf0
[   33.365028] [<ffff0000080d7b30>] process_one_work+0x12c/0x28c
[   33.370576] [<ffff0000080d7ce8>] worker_thread+0x58/0x3b8
[   33.376393] [<ffff0000080dd4a8>] kthread+0x100/0x12c
[   33.381776] [<ffff0000080836c0>] ret_from_fork+0x10/0x50

Fix this by disabling it as the first thing in phy_exit().

Fixes: e78f3d15e115 ("phy: qcom-qmp: new qmp phy driver for qcom-chipsets")
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index e17f035..2526971 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -751,8 +751,6 @@ static int qcom_qmp_phy_poweroff(struct phy *phy)
 	struct qmp_phy *qphy = phy_get_drvdata(phy);
 	struct qcom_qmp *qmp = qphy->qmp;
 
-	clk_disable_unprepare(qphy->pipe_clk);
-
 	regulator_bulk_disable(qmp->cfg->num_vregs, qmp->vregs);
 
 	return 0;
@@ -936,6 +934,8 @@ static int qcom_qmp_phy_exit(struct phy *phy)
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 	int i = cfg->num_clks;
 
+	clk_disable_unprepare(qphy->pipe_clk);
+
 	/* PHY reset */
 	qphy_setbits(qphy->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project