[PATCH] USB3/DWC3: Enable undefined length INCR burst type

From: Changming Huang
Date: Tue Dec 13 2016 - 04:23:41 EST


While enabling undefined length INCR burst type and INCR16 burst type,
get better write performance on NXP Layerscape platform:
around 3% improvement (from 364MB/s to 375MB/s).

Signed-off-by: Changming Huang <jerry.huang@xxxxxxx>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat@xxxxxxx>
---
drivers/usb/dwc3/core.c | 6 ++++++
drivers/usb/dwc3/core.h | 13 +++++++++++++
2 files changed, 19 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index fea4469..0e11891 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -621,6 +621,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
goto err0;
}

+ /* Enable Undefined Length INCR Burst Type and Enable INCR16 Burst */
+ reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
+ reg &= ~DWC3_GSBUSCFG0_INCRBRSTMASK;
+ reg |= DWC3_GSBUSCFG0_INCR16BRSTENA | DWC3_GSBUSCFG0_INCRBRSTENA;
+ dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
+
/*
* Write Linux Version Code to our GUID register so it's easy to figure
* out which kernel version a bug was found.
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6b60e42..8bfdb77 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -156,6 +156,19 @@

/* Bit fields */

+/* Global SoC Bus Configuration Register 0 */
+#define DWC3_GSBUSCFG0_DATABIGEND (1 << 11)
+#define DWC3_GSBUSCFG0_DESCBIGEND (1 << 10)
+#define DWC3_GSBUSCFG0_INCR256BRSTENA (1 << 7)
+#define DWC3_GSBUSCFG0_INCR128BRSTENA (1 << 6)
+#define DWC3_GSBUSCFG0_INCR64BRSTENA (1 << 5)
+#define DWC3_GSBUSCFG0_INCR32BRSTENA (1 << 4)
+#define DWC3_GSBUSCFG0_INCR16BRSTENA (1 << 3)
+#define DWC3_GSBUSCFG0_INCR8BRSTENA (1 << 2)
+#define DWC3_GSBUSCFG0_INCR4BRSTENA (1 << 1)
+#define DWC3_GSBUSCFG0_INCRBRSTENA (1 << 0)
+#define DWC3_GSBUSCFG0_INCRBRSTMASK 0xff
+
/* Global Debug Queue/FIFO Space Available Register */
#define DWC3_GDBGFIFOSPACE_NUM(n) ((n) & 0x1f)
#define DWC3_GDBGFIFOSPACE_TYPE(n) (((n) << 5) & 0x1e0)
--
1.7.9.5