usb: dwc3: gadget: Ignore Packet Pending bit

Currently the controller handles single stream only. So, Ignore Packet
Pending bit for stream selection and don't search for another stream if
the host sends Data Packet with PP=0 (for OUT direction) or ACK with
NumP=0 and PP=0 (for IN direction). This slightly improves the stream
performance.

Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/097ba9e104c143f7ba0195ebff29390ec3043692.1618282705.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6e9abfb..5a9b56b 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -403,6 +403,7 @@
 #define DWC3_DCFG_NUMP(n)      (((n) >> DWC3_DCFG_NUMP_SHIFT) & 0x1f)
 #define DWC3_DCFG_NUMP_MASK    (0x1f << DWC3_DCFG_NUMP_SHIFT)
 #define DWC3_DCFG_LPM_CAP      BIT(22)
+#define DWC3_DCFG_IGNSTRMPP    BIT(23)
 
 /* Device Control Register */
 #define DWC3_DCTL_RUN_STOP     BIT(31)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e1b04c9..ec7aabb 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2399,6 +2399,17 @@ static int __dwc3_gadget_start(struct dwc3 *dwc)
 
        dwc3_gadget_setup_nump(dwc);
 
+       /*
+        * Currently the controller handles single stream only. So, Ignore
+        * Packet Pending bit for stream selection and don't search for another
+        * stream if the host sends Data Packet with PP=0 (for OUT direction) or
+        * ACK with NumP=0 and PP=0 (for IN direction). This slightly improves
+        * the stream performance.
+        */
+       reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+       reg |= DWC3_DCFG_IGNSTRMPP;
+       dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
        /* Start with SuperSpeed Default */
        dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);