EHCI: Quirk flag for port power handling on overcurrent.

Commit 756aa6b3d536afe85e151138cb03a293998887b3 (ehci-hub: improved
over-current recovery) added port power cycling on overcurrent indications as
needed by the MPC8349 USB controller after resolving of the overcurrent
situation in order to have the host state machine assert the correct port
status again.

Commit 81463c1d707186adbbe534016cd1249edeab0dac (EHCI: only power off port if
over-current is active) solved a thus resulting issue of endless overcurrent
changes in combination with the MAX4967 USB power supply chip that signals
overcurrent when power is not enabled by only powering off a port if the
overcurrent is currently active.

Added quirks flag need_oc_pp_cycle in order to specify the needed behaviour as
there is no common behaviour that can comply with both requirements.
Activated the quirks handling for Freescale 83xx based boards.

Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 12 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index d81d2fcbff18..3be3df233a0e 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -370,6 +370,15 @@ static int ehci_fsl_setup(struct usb_hcd *hcd)
         /* EHCI registers start at offset 0x100 */
         ehci->caps = hcd->regs + 0x100;
 
+#ifdef CONFIG_PPC_83xx
+        /*
+         * Deal with MPC834X that need port power to be cycled after the power
+         * fault condition is removed. Otherwise the state machine does not
+         * reflect PORTSC[CSC] correctly.
+         */
+        ehci->need_oc_pp_cycle = 1;
+#endif
+
         hcd->has_tt = 1;
 
         retval = ehci_setup(hcd);
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 7b04ca96b585..9ab4a4d9768a 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -840,7 +840,8 @@ static int ehci_hub_control (
                          * power switching; they're allowed to just limit the
                          * current.  khubd will turn the power back on.
                          */
-                        if ((temp & PORT_OC) && HCS_PPC(ehci->hcs_params)) {
+                        if (((temp & PORT_OC) || (ehci->need_oc_pp_cycle))
+                                        && HCS_PPC(ehci->hcs_params)) {
                                 ehci_writel(ehci,
                                         temp & ~(PORT_RWC_BITS | PORT_POWER),
                                         status_reg);
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index e66699950997..7c978b23520d 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -199,6 +199,7 @@ struct ehci_hcd {			/* one per controller */
         unsigned                use_dummy_qh:1; /* AMD Frame List table quirk*/
         unsigned                has_synopsys_hc_bug:1; /* Synopsys HC */
         unsigned                frame_index_bug:1; /* MosChip (AKA NetMos) */
+        unsigned                need_oc_pp_cycle:1; /* MPC834X port power */
 
         /* required for usb32 quirk */
         #define OHCI_CTRL_HCFS          (3 << 6)