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, 3 insertions, 0 deletions

diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h
index 921cccf1ca9d..801be9e61340 100644
--- a/drivers/usb/cdns3/core.h
+++ b/drivers/usb/cdns3/core.h
@@ -79,6 +79,8 @@ struct cdns3_platform_data {
  * @pdata: platform data from glue layer
  * @lock: spinlock structure
  * @xhci_plat_data: xhci private data structure pointer
+ * @override_apb_timeout: hold value of APB timeout. For value 0 the default
+ *                        value in CHICKEN_BITS_3 will be preserved.
  * @gadget_init: pointer to gadget initialization function
  */
 struct cdns {
@@ -117,6 +119,7 @@ struct cdns {
 	struct cdns3_platform_data	*pdata;
 	spinlock_t			lock;
 	struct xhci_plat_priv		*xhci_plat_data;
+	u32                             override_apb_timeout;
 
 	int (*gadget_init)(struct cdns *cdns);
 };