By default when core sees any transaction error(CRC or overflow)
it replies with terminating retry ACK (Retry=1 and Nump == 0).
Enabling this Auto Retry feature in controller, on seeing any
transaction errors makes the core to send a non-terminating ACK
transaction packet (that is, ACK TP with Retry=1 and Nump != 0).
Doing so will give controller a chance to recover from the error
condition.
Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xxxxxxxxxx>
---
Changes in v4:
1. Changed the patch subject
Changes in v3:
1. As suggested by Felipe, added OTG related check
2. Corrected the multi-line commenting format
Changes in v2:
1. As suggested by Rob Herring & Felipe Balbi removed the
quirk logic and setting the AutoRetry bits unconditionally
for hostmode
---
drivers/usb/dwc3/core.c | 16 ++++++++++++++++
drivers/usb/dwc3/core.h | 3 +++
2 files changed, 19 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 1038075..bc9e33c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -883,6 +883,22 @@ static int dwc3_core_init(struct dwc3 *dwc)
dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
}
+ if (dwc->dr_mode == USB_DR_MODE_HOST ||
+ dwc->dr_mode == USB_DR_MODE_OTG) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
+
+ /*
+ * Enable Auto retry Feature to make the controller operating in
+ * Host mode on seeing transaction errors(CRC errors or internal
+ * overrun scenerios) on IN transfers to reply to the device
+ * with a non-terminating retry ACK (i.e, an ACK transcation
+ * packet with Retry=1 & Nump != 0)
+ */
+ reg |= DWC3_GUCTL_HSTINAUTORETRY;
+
+ dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
+ }
+
/*
* Must config both number of packets and max burst settings to enable
* RX and/or TX threshold.
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 285ce0e..92a1077 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -227,6 +227,9 @@
#define DWC3_GCTL_GBLHIBERNATIONEN BIT(1)
#define DWC3_GCTL_DSBLCLKGTNG BIT(0)
+/* Global User Control Register */
+#define DWC3_GUCTL_HSTINAUTORETRY BIT(14)
+
/* Global User Control 1 Register */
#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
#define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
--
2.1.1
--
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