usb: cdnsp: Fix issue with resuming from L1

In very rare cases after resuming controller from L1 to L0 it reads
registers before the clock UTMI have been enabled and as the result
driver reads incorrect value.
Most of registers are in APB domain clock but some of them (e.g. PORTSC)
are in UTMI domain clock.
After entering to L1 state the UTMI clock can be disabled.
When controller transition from L1 to L0 the port status change event is
reported and in interrupt runtime function driver reads PORTSC.
During this read operation controller synchronize UTMI and APB domain
but UTMI clock is still disabled and in result it reads 0xFFFFFFFF value.
To fix this issue driver increases APB timeout value.

The issue is platform specific and if the default value of APB timeout
is not sufficient then this time should be set Individually for each
platform.

Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/PH7PR07MB953846C57973E4DB134CAA71DDBF2@PH7PR07MB9538.namprd07.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/usb/cdns3/cdnsp-pci.c b/drivers/usb/cdns3/cdnsp-pci.c
index a51144504ff3..8c361b8394e9 100644
--- a/drivers/usb/cdns3/cdnsp-pci.c
+++ b/drivers/usb/cdns3/cdnsp-pci.c
@@ -28,6 +28,8 @@
 #define PCI_DRIVER_NAME		"cdns-pci-usbssp"
 #define PLAT_DRIVER_NAME	"cdns-usbssp"
 
+#define CHICKEN_APB_TIMEOUT_VALUE       0x1C20
+
 static struct pci_dev *cdnsp_get_second_fun(struct pci_dev *pdev)
 {
 	/*
@@ -139,6 +141,14 @@ static int cdnsp_pci_probe(struct pci_dev *pdev,
 		cdnsp->otg_irq = pdev->irq;
 	}
 
+	/*
+	 * Cadence PCI based platform require some longer timeout for APB
+	 * to fixes domain clock synchronization issue after resuming
+	 * controller from L1 state.
+	 */
+	cdnsp->override_apb_timeout = CHICKEN_APB_TIMEOUT_VALUE;
+	pci_set_drvdata(pdev, cdnsp);
+
 	if (pci_is_enabled(func)) {
 		cdnsp->dev = dev;
 		cdnsp->gadget_init = cdnsp_gadget_init;
@@ -148,8 +158,6 @@ static int cdnsp_pci_probe(struct pci_dev *pdev,
 			goto free_cdnsp;
 	}
 
-	pci_set_drvdata(pdev, cdnsp);
-
 	device_wakeup_enable(&pdev->dev);
 	if (pci_dev_run_wake(pdev))
 		pm_runtime_put_noidle(&pdev->dev);