Hi,
On 10-09-18 13:51, Mika Westerberg wrote:
On Sat, Sep 08, 2018 at 08:08:13PM +0200, Hans de Goede wrote:
lpss_iosf_enter_d3_state() checks if all hw-blocks using the DMA
controllers are in d3 before powering down the DMA controllers.
But on devices, where the I2C bus connected to the PMIC is shared by
the PUNIT, the controller for that bus will never reach d3 since it has
an effectively empty _PS3 method. Instead it appears to automatically
power-down during S0i3 and we never see it as being in d3.
This causes the DMA controllers to never be powered-down on these devices,
causing them to never reach S0i3. This commit uses the ACPI _SEM method
to detect if an I2C bus is shared with the PUNIT and if it is, it removes
it from the mask of devices which lpss_iosf_enter_d3_state() checks for.
This fixes these devices never reaching any S0ix states.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/acpi/acpi_lpss.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 969bf8d515c0..83875305b1d4 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -99,6 +99,9 @@ struct lpss_private_data {
u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
};
+/* Devices which need to be in D3 before lpss_iosf_enter_d3_state() proceeds */
+static u32 pmc_atom_d3_mask = 0xfe000ffe;
+
/* LPSS run time quirks */
static unsigned int lpss_quirks;
@@ -175,6 +178,21 @@ static void byt_pwm_setup(struct lpss_private_data *pdata)
static void byt_i2c_setup(struct lpss_private_data *pdata)
{
+ const char *uid_str = acpi_device_uid(pdata->adev);
+ acpi_handle handle = pdata->adev->handle;
+ unsigned long long shared_host = 0;
+ acpi_status status;
+ long uid = 0;
Hmm, I wonder if uid=0 is actually valid? IIRC they start from 0 and go
forward from that.
You are right some devices have 0 based UIDs but not the I2C controllers
on BYT/CHT those have 1 based UIDs.
+
+ /* Expected to always be true, but better safe then sorry */
+ if (uid_str)
+ uid = simple_strtol(uid_str, NULL, 10);
+
+ /* Detect I2C bus shared with PUNIT and ignore its d3 status */
+ status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
+ if (ACPI_SUCCESS(status) && shared_host && uid)
+ pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
Hence also the - 1 here.
Regards,
Hans
