| From d79294d0de12ddd1420110813626d691f440b86f Mon Sep 17 00:00:00 2001 |
| From: Hans de Goede <hdegoede@redhat.com> |
| Date: Tue, 7 Apr 2020 20:11:16 +0200 |
| Subject: i2c: designware: platdrv: Remove DPM_FLAG_SMART_SUSPEND flag on BYT and CHT |
| |
| From: Hans de Goede <hdegoede@redhat.com> |
| |
| commit d79294d0de12ddd1420110813626d691f440b86f upstream. |
| |
| We already set DPM_FLAG_SMART_PREPARE, so we completely skip all |
| callbacks (other then prepare) where possible, quoting from |
| dw_i2c_plat_prepare(): |
| |
| /* |
| * If the ACPI companion device object is present for this device, it |
| * may be accessed during suspend and resume of other devices via I2C |
| * operation regions, so tell the PM core and middle layers to avoid |
| * skipping system suspend/resume callbacks for it in that case. |
| */ |
| return !has_acpi_companion(dev); |
| |
| Also setting the DPM_FLAG_SMART_SUSPEND will cause acpi_subsys_suspend() |
| to leave the controller runtime-suspended even if dw_i2c_plat_prepare() |
| returned 0. |
| |
| Leaving the controller runtime-suspended normally, when the I2C controller |
| is suspended during the suspend_late phase, is not an issue because |
| the pm_runtime_get_sync() done by i2c_dw_xfer() will (runtime-)resume it. |
| |
| But for dw I2C controllers on Bay- and Cherry-Trail devices acpi_lpss.c |
| leaves the controller alive until the suspend_noirq phase, because it may |
| be used by the _PS3 ACPI methods of PCI devices and PCI devices are left |
| powered on until the suspend_noirq phase. |
| |
| Between the suspend_late and resume_early phases runtime-pm is disabled. |
| So for any ACPI I2C OPRegion accesses done after the suspend_late phase, |
| the pm_runtime_get_sync() done by i2c_dw_xfer() is a no-op and the |
| controller is left runtime-suspended. |
| |
| i2c_dw_xfer() has a check to catch this condition (rather then waiting |
| for the I2C transfer to timeout because the controller is suspended). |
| acpi_subsys_suspend() leaving the controller runtime-suspended in |
| combination with an ACPI I2C OPRegion access done after the suspend_late |
| phase triggers this check, leading to the following error being logged |
| on a Bay Trail based Lenovo Thinkpad 8 tablet: |
| |
| [ 93.275882] i2c_designware 80860F41:00: Transfer while suspended |
| [ 93.275993] WARNING: CPU: 0 PID: 412 at drivers/i2c/busses/i2c-designware-master.c:429 i2c_dw_xfer+0x239/0x280 |
| ... |
| [ 93.276252] Workqueue: kacpi_notify acpi_os_execute_deferred |
| [ 93.276267] RIP: 0010:i2c_dw_xfer+0x239/0x280 |
| ... |
| [ 93.276340] Call Trace: |
| [ 93.276366] __i2c_transfer+0x121/0x520 |
| [ 93.276379] i2c_transfer+0x4c/0x100 |
| [ 93.276392] i2c_acpi_space_handler+0x219/0x510 |
| [ 93.276408] ? up+0x40/0x60 |
| [ 93.276419] ? i2c_acpi_notify+0x130/0x130 |
| [ 93.276433] acpi_ev_address_space_dispatch+0x1e1/0x252 |
| ... |
| |
| So since on BYT and CHT platforms we want ACPI I2c OPRegion accesses |
| to work until the suspend_noirq phase, we need the controller to be |
| runtime-resumed during the suspend phase if it is runtime-suspended |
| suspended at that time. This means that we must not set the |
| DPM_FLAG_SMART_SUSPEND on these platforms. |
| |
| On BYT and CHT we already have a special ACCESS_NO_IRQ_SUSPEND flag |
| to make sure the controller stays functional until the suspend_noirq |
| phase. This commit makes the driver not set the DPM_FLAG_SMART_SUSPEND |
| flag when that flag is set. |
| |
| Cc: stable@vger.kernel.org |
| Fixes: b30f2f65568f ("i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers") |
| Signed-off-by: Hans de Goede <hdegoede@redhat.com> |
| Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
| Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> |
| Signed-off-by: Wolfram Sang <wsa@the-dreams.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/i2c/busses/i2c-designware-platdrv.c | 14 ++++++++++---- |
| 1 file changed, 10 insertions(+), 4 deletions(-) |
| |
| --- a/drivers/i2c/busses/i2c-designware-platdrv.c |
| +++ b/drivers/i2c/busses/i2c-designware-platdrv.c |
| @@ -370,10 +370,16 @@ static int dw_i2c_plat_probe(struct plat |
| adap->dev.of_node = pdev->dev.of_node; |
| adap->nr = -1; |
| |
| - dev_pm_set_driver_flags(&pdev->dev, |
| - DPM_FLAG_SMART_PREPARE | |
| - DPM_FLAG_SMART_SUSPEND | |
| - DPM_FLAG_LEAVE_SUSPENDED); |
| + if (dev->flags & ACCESS_NO_IRQ_SUSPEND) { |
| + dev_pm_set_driver_flags(&pdev->dev, |
| + DPM_FLAG_SMART_PREPARE | |
| + DPM_FLAG_LEAVE_SUSPENDED); |
| + } else { |
| + dev_pm_set_driver_flags(&pdev->dev, |
| + DPM_FLAG_SMART_PREPARE | |
| + DPM_FLAG_SMART_SUSPEND | |
| + DPM_FLAG_LEAVE_SUSPENDED); |
| + } |
| |
| /* The code below assumes runtime PM to be disabled. */ |
| WARN_ON(pm_runtime_enabled(&pdev->dev)); |