On 03/09/17 17:00, Jarkko Nikula wrote:
+ Tianyu On 03/08/17 10:47, Hans de Goede wrote:Cherrytrail devices use the dw i2c-bus with uid 7 to access their PMIC. Even if the i2c-bus to the PMIC is not shared with the SoC's P-Unit and i2c-designware-baytrail.c thus does not set the pm_disabled flag, we still need to disable pm so that ACPI PMIC opregions can access the PMIC during late-suspend and early-resume. This fixes errors like these blocking suspend: i2c_designware 808622C1:06: timeout waiting for bus ready ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion] acpi 80860F14:02: Failed to change power state to D3hot PM: late suspend of devices failed Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/i2c/busses/i2c-designware-platdrv.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 8ed96dd..08d609e 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -94,7 +94,10 @@ static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], static int dw_i2c_acpi_configure(struct platform_device *pdev) { struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + acpi_handle handle = ACPI_HANDLE(&pdev->dev); const struct acpi_device_id *id; + struct acpi_device *adev; + const char *uid; dev->adapter.nr = -1; dev->tx_fifo_depth = 32; @@ -114,6 +117,18 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) if (id && id->driver_data) dev->flags |= (u32)id->driver_data; + if (acpi_bus_get_device(handle, &adev)) + return -ENODEV; + + /* + * Cherrytrail I2C7 gets used for the PMIC which gets accessed + * through ACPI opregions during late suspend / early resume + * disable pm for it. + */ + uid = adev->pnp.unique_id; + if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7")) + dev->pm_disabled = true; +I'm fine with this but wondering can this be detected any other way than hardcoded bus number. Tianyu: You are the author of 5d98e61d337c ("I2C/ACPI: Add i2c ACPI operation region support"). Do you know is there way to see is there a PMIC connected to the bus? Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Here too: Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
