diff options
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 67892fc0b822..a8d7d83ac761 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -67,7 +67,15 @@ ACPI_MODULE_NAME("acpi_lpss"); #define LPSS_CLK_DIVIDER BIT(2) #define LPSS_LTR BIT(3) #define LPSS_SAVE_CTX BIT(4) -#define LPSS_NO_D3_DELAY BIT(5) +/* + * For some devices the DSDT AML code for another device turns off the device + * before our suspend handler runs, causing us to read/save all 1-s (0xffffffff) + * as ctx register values. + * Luckily these devices always use the same ctx register values, so we can + * work around this by saving the ctx registers once on activation. + */ +#define LPSS_SAVE_CTX_ONCE BIT(5) +#define LPSS_NO_D3_DELAY BIT(6) struct lpss_private_data; @@ -254,7 +262,7 @@ static const struct lpss_device_desc byt_pwm_dev_desc = { }; static const struct lpss_device_desc bsw_pwm_dev_desc = { - .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, + .flags = LPSS_SAVE_CTX_ONCE | LPSS_NO_D3_DELAY, .prv_offset = 0x800, .setup = bsw_pwm_setup, .resume_from_noirq = true, @@ -885,9 +893,14 @@ static int acpi_lpss_activate(struct device *dev) * we have to deassert reset line to be sure that ->probe() will * recognize the device. */ - if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE)) lpss_deassert_reset(pdata); +#ifdef CONFIG_PM + if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE) + acpi_lpss_save_ctx(dev, pdata); +#endif + return 0; } @@ -1031,7 +1044,7 @@ static int acpi_lpss_resume(struct device *dev) acpi_lpss_d3_to_d0_delay(pdata); - if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE)) acpi_lpss_restore_ctx(dev, pdata); return 0; |