[PATCH 5.11 292/601] spi: spi-zynqmp-gqspi: fix clk_enable/disable imbalance issue

Greg Kroah-Hartman
2021-05-12T17:30:59Z

From: Quanyang Wang <quanyang.wang@windriver.com>

[ Upstream commit c6bdae08012b2ca3e94f3a41ef4ca8cfe7c9ab6f ]

The clks "pclk" and "ref_clk" are enabled twice during the probe. The
first time is in the function zynqmp_qspi_probe and the second time is
in zynqmp_qspi_setup_op which is called by devm_spi_register_controller.
Then calling zynqmp_qspi_remove (rmmod this module) to disable these clks
will trigger a warning as below:

[ 309.124604] Unpreparing enabled qspi_ref
[ 309.128641] WARNING: CPU: 1 PID: 537 at drivers/clk/clk.c:824 clk_core_unprepare+0x108/0x110

Since pm_runtime works now, clks can be enabled/disabled by calling
zynqmp_runtime_suspend/resume. So we don't need to enable these clks
explicitly in zynqmp_qspi_setup_op. Remove them to fix this issue.

And remove clk enabling/disabling in zynqmp_qspi_resume because there is
no spi transfer operation so enabling ref_clk is redundant meanwhile pclk
is not disabled for it is shared with other peripherals.

Furthermore replace clk_enable/disable with clk_prepare_enable and
clk_disable_unprepare in runtime_suspend/resume functions.

Fixes: 1c26372e5aa9 ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Link: https://lore.kernel.org/r/20210416004652.2975446-2-quanyang.wang@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-zynqmp-gqspi.c | 47 ++++++----------------------------
1 file changed, 8 insertions(+), 39 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 408e348382c5..31d266cfbb4c 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -487,24 +487,10 @@ static int zynqmp_qspi_setup_op(struct spi_device *qspi)
{
struct spi_controller *ctlr = qspi->master;
struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);
- struct device *dev = &ctlr->dev;
- int ret;

if (ctlr->busy)
return -EBUSY;

- ret = clk_enable(xqspi->refclk);
- if (ret) {
- dev_err(dev, "Cannot enable device clock.\n");
- return ret;
- }
-
- ret = clk_enable(xqspi->pclk);
- if (ret) {
- dev_err(dev, "Cannot enable APB clock.\n");
- clk_disable(xqspi->refclk);
- return ret;
- }
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);

return 0;
@@ -863,26 +849,9 @@ static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
- struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);
- int ret = 0;
-
- ret = clk_enable(xqspi->pclk);
- if (ret) {
- dev_err(dev, "Cannot enable APB clock.\n");
- return ret;
- }
-
- ret = clk_enable(xqspi->refclk);
- if (ret) {
- dev_err(dev, "Cannot enable device clock.\n");
- clk_disable(xqspi->pclk);
- return ret;
- }

spi_controller_resume(ctlr);

- clk_disable(xqspi->refclk);
- clk_disable(xqspi->pclk);
return 0;
}

@@ -898,8 +867,8 @@ static int __maybe_unused zynqmp_runtime_suspend(struct device *dev)
{
struct zynqmp_qspi *xqspi = (struct zynqmp_qspi *)dev_get_drvdata(dev);

- clk_disable(xqspi->refclk);
- clk_disable(xqspi->pclk);
+ clk_disable_unprepare(xqspi->refclk);
+ clk_disable_unprepare(xqspi->pclk);

return 0;
}
@@ -917,16 +886,16 @@ static int __maybe_unused zynqmp_runtime_resume(struct device *dev)
struct zynqmp_qspi *xqspi = (struct zynqmp_qspi *)dev_get_drvdata(dev);
int ret;

- ret = clk_enable(xqspi->pclk);
+ ret = clk_prepare_enable(xqspi->pclk);
if (ret) {
dev_err(dev, "Cannot enable APB clock.\n");
return ret;
}

- ret = clk_enable(xqspi->refclk);
+ ret = clk_prepare_enable(xqspi->refclk);
if (ret) {
dev_err(dev, "Cannot enable device clock.\n");
- clk_disable(xqspi->pclk);
+ clk_disable_unprepare(xqspi->pclk);
return ret;
}

@@ -1136,13 +1105,11 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
goto remove_master;
}

- init_completion(&xqspi->data_completion);
-
xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
if (IS_ERR(xqspi->refclk)) {
dev_err(dev, "ref_clk clock not found.\n");
ret = PTR_ERR(xqspi->refclk);
- goto clk_dis_pclk;
+ goto remove_master;
}

ret = clk_prepare_enable(xqspi->pclk);
@@ -1157,6 +1124,8 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
goto clk_dis_pclk;
}

+ init_completion(&xqspi->data_completion);
+
mutex_init(&xqspi->op_lock);

pm_runtime_use_autosuspend(&pdev->dev);
--
2.30.2