xhci: Use soft retry to recover faster from transaction errors
Use soft retry to recover from a USB Transaction Errors that are caused by
temporary error conditions. The USB device is not aware that the xHC
has halted the endpoint, and will be waiting for another retry
A Soft Retry perform additional retries and recover from an error which has
caused the xHC to halt an endpoint.
Soft retry has some limitations:
Soft Retry attempts shall not be performed on Isoch endpoints
Soft Retry attempts shall not be performed if the device is behind a TT in
a HS Hub
Software shall limit the number of unsuccessful Soft Retry attempts to
prevent an infinite loop.
For more details on Soft retry see xhci specs 4.6.8.1
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 6230a57..b635785 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1496,6 +1496,7 @@ static inline const char *xhci_trb_type_string(u8 type)
/* How much data is left before the 64KB boundary? */
#define TRB_BUFF_LEN_UP_TO_BOUNDARY(addr) (TRB_MAX_BUFF_SIZE - \
(addr & (TRB_MAX_BUFF_SIZE - 1)))
+#define MAX_SOFT_RETRY 3
struct xhci_segment {
union xhci_trb *trbs;
@@ -1583,6 +1584,7 @@ struct xhci_ring {
* if we own the TRB (if we are the consumer). See section 4.9.1.
*/
u32 cycle_state;
+ unsigned int err_count;
unsigned int stream_id;
unsigned int num_segs;
unsigned int num_trbs_free;