On 21/03/2019 15:33, Sameer Pujar wrote:
> gic-pm driver is using pm_clk_*() interface to manage clock resources. With
> this, clocks always remain ON. This happens on Tegra devices which use BPMP
> co-processor to manage the clocks, where clocks are enabled during prepare
> phase. This is necessary because calls to BPMP are always blocking. When
> pm_clk_*() interface is used on such devices, clock prepare count is not
> balanced till driver remove() gets executed and hence clocks are seen ON
> always. This patch helps to keep clock ref counts balanced and thus clocks
> are off, when device not in use.
>
> Please note that this works for any device and the fix is not specific to
> Tegra devices.
>
> Suggested-by: Mohan Kumar D <mkumard@xxxxxxxxxx>
> Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
> Reviewed-by: Jonathan Hunter <jonathanh@xxxxxxxxxx>
Not yet!
> ---
> drivers/irqchip/irq-gic-pm.c | 68 ++++++++++++++++++++++++++------------------
> 1 file changed, 41 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-pm.c b/drivers/irqchip/irq-gic-pm.c
> index ecafd29..b557a53 100644
> --- a/drivers/irqchip/irq-gic-pm.c
> +++ b/drivers/irqchip/irq-gic-pm.c
> @@ -19,7 +19,6 @@
> #include <linux/of_irq.h>
> #include <linux/irqchip/arm-gic.h>
> #include <linux/platform_device.h>
> -#include <linux/pm_clock.h>
> #include <linux/pm_runtime.h>
> #include <linux/slab.h>
>
> @@ -28,14 +27,24 @@ struct gic_clk_data {
> const char *const *clocks;
> };
>
> +struct gic_chip_pm {
> + struct gic_chip_data *chip_data;
> + const struct gic_clk_data *clk_data;
> + struct clk_bulk_data *clks;
> +};
> +
> static int gic_runtime_resume(struct device *dev)
> {
> - struct gic_chip_data *gic = dev_get_drvdata(dev);
> + struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
> + struct gic_chip_data *gic = chip_pm->chip_data;
> + const struct gic_clk_data *data = chip_pm->clk_data;
> int ret;
>
> - ret = pm_clk_resume(dev);
> - if (ret)
> + ret = clk_bulk_prepare_enable(data->num_clocks, chip_pm->clks);
> + if (ret) {
> + dev_err(dev, " clk_enable failed: %d\n", ret);
Unnecessary space here.
> return ret;
> + }
>
> /*
> * On the very first resume, the pointer to the driver data
> @@ -54,51 +63,59 @@ static int gic_runtime_resume(struct device *dev)
>
> static int gic_runtime_suspend(struct device *dev)
> {
> - struct gic_chip_data *gic = dev_get_drvdata(dev);
> + struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
> + struct gic_chip_data *gic = chip_pm->chip_data;
> + const struct gic_clk_data *data = chip_pm->clk_data;
>
> gic_dist_save(gic);
> gic_cpu_save(gic);
>
> - return pm_clk_suspend(dev);
> + clk_bulk_disable_unprepare(data->num_clocks, chip_pm->clks);
> +
> + return 0;
> }
>
> -static int gic_get_clocks(struct device *dev, const struct gic_clk_data *data)
> +static int gic_get_clocks(struct device *dev, struct gic_chip_pm *chip_pm)
> {
> + const struct gic_clk_data *data = chip_pm->clk_data;
> unsigned int i;
> - int ret;
>
> if (!dev || !data)
> return -EINVAL;
>
> - ret = pm_clk_create(dev);
> - if (ret)
> - return ret;
> + chip_pm->clks =
> + devm_kzalloc(dev,
> + data->num_clocks * sizeof(struct clk_bulk_data),
> + GFP_KERNEL);
Ugh, please sort out the formatting here. No reason why devm_kzalloc
cannot start on the same line as chip_pm->clks. You should use
devm_kcalloc here and for sizeof use sizeof(*chip_pm->clks).
>
> - for (i = 0; i < data->num_clocks; i++) {
> - ret = of_pm_clk_add_clk(dev, data->clocks[i]);
> - if (ret) {
> - dev_err(dev, "failed to add clock %s\n",
> - data->clocks[i]);
> - pm_clk_destroy(dev);
> - return ret;
> - }
> - }
> + if (!chip_pm->clks)
> + return -ENOMEM;
>
> - return 0;
> + for (i = 0; i < data->num_clocks; i++)
> + chip_pm->clks[i].id = data->clocks[i];
Hmm ... that's unfortunate but I don't have a better idea to avoid this :-(
> +
> + return devm_clk_bulk_get(dev, data->num_clocks, chip_pm->clks);
> }
>
> static int gic_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> const struct gic_clk_data *data;
> - struct gic_chip_data *gic;
> + struct gic_chip_pm *chip_pm;
> int ret, irq;
>
> + chip_pm = devm_kzalloc(dev, sizeof(struct gic_chip_pm),
sizeof(*chip_pm)
> + GFP_KERNEL);
> + if (!chip_pm)
> + return -ENOMEM;
> +
> data = of_device_get_match_data(&pdev->dev);
> if (!data) {
> dev_err(&pdev->dev, "no device match found\n");
> return -ENODEV;
> }
> + chip_pm->clk_data = data;
> + platform_set_drvdata(pdev, chip_pm);
So why has this been moved? There is a comment in gic_runtime_resume()
on why this was set after pm_runtime_get_sync() in probe.
Cheers
Jon
--
nvpublic
