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authorFaisal Hassan <quic_faisalh@quicinc.com>2024-11-29 23:04:22 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-12-04 16:09:41 +0100
commit04d5b4c23f3b7cbf44a71a338dae0c7aabd86c29 (patch)
tree64f5d91ce54c944b639a4c5c775cd928ec244e29 /drivers/usb/dwc3/core.c
parenta787bffff5d14545c8e2d061b6f7839ede8ead19 (diff)
usb: dwc3: core: Disable USB2 retry for DWC_usb31 1.80a and prior
STAR 9001346572 addresses a USB 2.0 endpoint blocking issue in host mode for controller versions DWC_usb31 1.70a and 1.80a. This issue affects devices on both high-speed and full-speed bus instances. When all endpoint caches are filled and a single active endpoint receives continuous NAK responses, data transfers to other endpoints may get blocked. To resolve this, for controller versions DWC_usb31 1.70a and 1.80a, the GUCTL3 bit[16] (USB2.0 Internal Retry Disable) is set to 1. This bit disables the USB2.0 internal retry feature and ensures proper eviction handling in the host controller endpoind cache. The GUCTL3[16] register function is available only from DWC_usb31 version 1.70a. Signed-off-by: Faisal Hassan <quic_faisalh@quicinc.com> Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/20241129173422.20063-1-quic_faisalh@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/core.c')
-rw-r--r--drivers/usb/dwc3/core.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index f219c82e9619..c22b8678e02e 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1479,6 +1479,26 @@ static int dwc3_core_init(struct dwc3 *dwc)
}
}
+ /*
+ * STAR 9001346572: This issue affects DWC_usb31 versions 1.80a and
+ * prior. When an active endpoint not currently cached in the host
+ * controller is chosen to be cached to the same index as an endpoint
+ * receiving NAKs, the endpoint receiving NAKs enters continuous
+ * retry mode. This prevents it from being evicted from the host
+ * controller cache, blocking the new endpoint from being cached and
+ * serviced.
+ *
+ * To resolve this, for controller versions 1.70a and 1.80a, set the
+ * GUCTL3 bit[16] (USB2.0 Internal Retry Disable) to 1. This bit
+ * disables the USB2.0 internal retry feature. The GUCTL3[16] register
+ * function is available only from version 1.70a.
+ */
+ if (DWC3_VER_IS_WITHIN(DWC31, 170A, 180A)) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
+ reg |= DWC3_GUCTL3_USB20_RETRY_DISABLE;
+ dwc3_writel(dwc->regs, DWC3_GUCTL3, reg);
+ }
+
return 0;
err_power_off_phy: