On Monday, September 25, 2017 9:23:52 PM CET Johannes Stezenbach wrote:
> d31fd43c0f9a "clk: x86: Do not gate clocks enabled by the firmware"
> exposed an issue on Asus E200HA where BIOS enables unused
> Atom PMC clocks which prevent the system from entering S0ix.
> Add a quirk to disable these clocks on E200HA.
>
> Signed-off-by: Johannes Stezenbach <js@xxxxxxxxx>
Mika, Andy, Hans, any comments here?
> ---
> drivers/clk/x86/clk-pmc-atom.c | 10 +++++++---
> drivers/platform/x86/pmc_atom.c | 7 ++++++-
> include/linux/platform_data/x86/clk-pmc-atom.h | 2 ++
> 3 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/x86/clk-pmc-atom.c b/drivers/clk/x86/clk-pmc-atom.c
> index 08ef69945ffb..213e71b905eb 100644
> --- a/drivers/clk/x86/clk-pmc-atom.c
> +++ b/drivers/clk/x86/clk-pmc-atom.c
> @@ -166,7 +166,8 @@ static const struct clk_ops plt_clk_ops = {
> static struct clk_plt *plt_clk_register(struct platform_device *pdev, int id,
> void __iomem *base,
> const char **parent_names,
> - int num_parents)
> + int num_parents,
> + bool disable_unused)
> {
> struct clk_plt *pclk;
> struct clk_init_data init;
> @@ -190,7 +191,7 @@ static struct clk_plt *plt_clk_register(struct platform_device *pdev, int id,
> * If the clock was already enabled by the firmware mark it as critical
> * to avoid it being gated by the clock framework if no driver owns it.
> */
> - if (plt_clk_is_enabled(&pclk->hw))
> + if (!disable_unused && plt_clk_is_enabled(&pclk->hw))
> init.flags |= CLK_IS_CRITICAL;
>
> ret = devm_clk_hw_register(&pdev->dev, &pclk->hw);
> @@ -324,6 +325,7 @@ static int plt_clk_probe(struct platform_device *pdev)
> struct clk_plt_data *data;
> unsigned int i;
> int err;
> + bool disable_unused;
>
> pmc_data = dev_get_platdata(&pdev->dev);
> if (!pmc_data || !pmc_data->clks)
> @@ -337,9 +339,11 @@ static int plt_clk_probe(struct platform_device *pdev)
> if (IS_ERR(parent_names))
> return PTR_ERR(parent_names);
>
> + disable_unused = !!(pmc_data->flags & PMC_CLK_DATA_DISABLE_UNUSED);
> for (i = 0; i < PMC_CLK_NUM; i++) {
> data->clks[i] = plt_clk_register(pdev, i, pmc_data->base,
> - parent_names, data->nparents);
> + parent_names, data->nparents,
> + disable_unused);
> if (IS_ERR(data->clks[i])) {
> err = PTR_ERR(data->clks[i]);
> goto err_unreg_clk_plt;
> diff --git a/drivers/platform/x86/pmc_atom.c b/drivers/platform/x86/pmc_atom.c
> index b5dd38712268..d81ada1a6f27 100644
> --- a/drivers/platform/x86/pmc_atom.c
> +++ b/drivers/platform/x86/pmc_atom.c
> @@ -59,7 +59,8 @@ static struct pmc_dev pmc_device;
> static u32 acpi_base_addr;
>
> static u32 quirks;
> -#define QUIRK_DISABLE_SATA BIT(0)
> +#define QUIRK_DISABLE_SATA BIT(0)
> +#define QUIRK_DISABLE_UNUSED_CLOCKS BIT(1)
>
> static const struct pmc_clk byt_clks[] = {
> {
> @@ -447,6 +448,8 @@ static int pmc_setup_clks(struct pci_dev *pdev, void __iomem *pmc_regmap,
>
> clk_data->base = pmc_regmap; /* offset is added by client */
> clk_data->clks = pmc_data->clks;
> + if (quirks & QUIRK_DISABLE_UNUSED_CLOCKS)
> + clk_data->flags = PMC_CLK_DATA_DISABLE_UNUSED;
>
> clkdev = platform_device_register_data(&pdev->dev, "clk-pmc-atom",
> PLATFORM_DEVID_NONE,
> @@ -517,6 +520,8 @@ static int cht_asus_e200ha_cb(const struct dmi_system_id *id)
> {
> pr_info("pmc: Asus E200HA detected\n");
> quirks |= QUIRK_DISABLE_SATA;
> + /* BIOS enables some clocks at boot which are not needed but block S0ix */
> + quirks |= QUIRK_DISABLE_UNUSED_CLOCKS;
> return 1;
> }
>
> diff --git a/include/linux/platform_data/x86/clk-pmc-atom.h b/include/linux/platform_data/x86/clk-pmc-atom.h
> index 3ab892208343..e481878ef238 100644
> --- a/include/linux/platform_data/x86/clk-pmc-atom.h
> +++ b/include/linux/platform_data/x86/clk-pmc-atom.h
> @@ -37,6 +37,8 @@ struct pmc_clk {
> * @clks: pointer to set of registered clocks, typically 0..5
> */
> struct pmc_clk_data {
> + int flags;
> +#define PMC_CLK_DATA_DISABLE_UNUSED 1
> void __iomem *base;
> const struct pmc_clk *clks;
> };
>
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