drivers: usb: fsl: Workaround for Erratum A004477

[platform/kernel/u-boot.git] / drivers / usb / host / ehci-fsl.c

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 2dca524..5fd618d 100644 (file)
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -138,6 +138,16 @@ int ehci_hcd_init(int index, enum usb_init_type init,
        if (has_erratum_a007798())
                set_txfifothresh(ehci, TXFIFOTHRESH);
 
+       if (has_erratum_a004477()) {
+               /*
+                * When reset is issued while any ULPI transaction is ongoing
+                * then it may result to corruption of ULPI Function Control
+                * Register which eventually causes phy clock to enter low
+                * power mode which stops the clock. Thus delay is required
+                * before reset to let ongoing ULPI transaction complete.
+                */
+               udelay(1);
+       }
        return 0;
 }