Unverified Commit c6bdae08 authored by Quanyang Wang's avatar Quanyang Wang Committed by Mark Brown
Browse files

spi: spi-zynqmp-gqspi: fix clk_enable/disable imbalance issue 



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: 1c26372e ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: default avatarQuanyang Wang <quanyang.wang@windriver.com>
Link: https://lore.kernel.org/r/20210416004652.2975446-2-quanyang.wang@windriver.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c7ed5fd5

drivers/spi/spi-zynqmp-gqspi.c

+8 −39
Original line number Diff line number Diff line
@@ -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);