On 10/18/2024 4:32 PM, AKASH KUMAR wrote:
Hi Uttkarsh, Thinh,
On 10/17/2024 5:10 PM, Uttkarsh Aggarwal wrote:
Currently in few of Qualcomm chips USB (Low speed) mouse not
detected showing following errors:
usb 1-1: Device not responding to setup address.
usb 1-1: device not accepting address 2, error -71
usb 1-1: new low-speed USB device number 3 using xhci-hcd
usb 1-1: Device not responding to setup address.
usb 1-1: Device not responding to setup address.
usb 1-1: device not accepting address 3, error -71
usb usb1-port1: attempt power cycle
Based on the Logic analyzer waveforms, It has been identified that there
is skew of about 8nS b/w DP & DM linestate signals (o/p of PHY & i/p to
controller) at the UTMI interface, Due to this controller is seeing SE0
glitch condition, this is causing controller to pre-maturely assume that
PHY has sent all the data & is initiating next packet much early, though
in reality PHY is still busy sending previous packets.
Enabling the GUCTL1.FILTER_SE0_FSLS_EOP bit29 allows the controller to
ignore single SE0 glitches on the linestate during transmission. Only
two
or more SE0 signals are recognized as a valid EOP.
When this feature is activated, SE0 signals on the linestate are
validated
over two consecutive UTMI/ULPI clock edges for EOP detection.
Device mode (FS): If GUCTL1.FILTER_SE0_FSLS_EOP is set, then for
device LPM
handshake, the controller ignores single SE0 glitch on the linestate
during
transmit. Only two or more SE0 is considered as a valid EOP on FS port.
Host mode (FS/LS): If GUCTL1.FILTER_SE0_FSLS_EOP is set, then the
controller
ignores single SE0 glitch on the linestate during transmit.
Signed-off-by: Uttkarsh Aggarwal<quic_uaggarwa@xxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 13 +++++++++++++
drivers/usb/dwc3/core.h | 4 ++++
2 files changed, 17 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 86b37881aab4..4edd32c44e73 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -222,6 +222,17 @@ static void __dwc3_set_mode(struct work_struct
*work)
switch (desired_dr_role) {
case DWC3_GCTL_PRTCAP_HOST:
+ /*
+ * Setting GUCTL1 bit 29 so that controller
+ * will ignore single SE0 glitch on the linestate
+ * during transmit.
+ */
+ if (dwc->filter_se0_fsls_eop_quirk) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
+ reg |= DWC3_GUCTL1_FILTER_SE0_FSLS_EOP;
+ dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
+ }
+
Since this bit is useful for device mode as well along with host
mode,we should set this in dwc3_core_init
where we are already writing for GUCTL1 bit disable parkmode, instead
of host mode only. Like below
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1444,6 +1444,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
if (dwc->parkmode_disable_hs_quirk)
reg |= DWC3_GUCTL1_PARKMODE_DISABLE_HS;
+ if (dwc->filter_se0_fsls_eop_quirk)
+ reg |= DWC3_GUCTL1_FILTER_SE0_FSLS_EOP;
+
if (DWC3_VER_IS_WITHIN(DWC3, 290A, ANY)) {
if (dwc->maximum_speed == USB_SPEED_FULL ||
dwc->maximum_speed == USB_SPEED_HIGH)
ret = dwc3_host_init(dwc);
if (ret) {
dev_err(dwc->dev, "failed to initialize host\n");
@@ -1788,6 +1799,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
"snps,tx_de_emphasis_quirk");
+ dwc->filter_se0_fsls_eop_quirk = device_property_read_bool(dev,
+ "snps,filter-se0-fsls-eop-quirk");
device_property_read_u8(dev, "snps,tx_de_emphasis",
&tx_de_emphasis);
device_property_read_string(dev, "snps,hsphy_interface",
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index cc3f32acfaf5..33d53a436fd7 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -276,6 +276,7 @@
/* Global User Control 1 Register */
#define DWC3_GUCTL1_DEV_DECOUPLE_L1L2_EVT BIT(31)
+#define DWC3_GUCTL1_FILTER_SE0_FSLS_EOP BIT(29)
#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
#define DWC3_GUCTL1_DEV_FORCE_20_CLK_FOR_30_CLK BIT(26)
#define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
@@ -1140,6 +1141,8 @@ struct dwc3_scratchpad_array {
* @gfladj_refclk_lpm_sel: set if we need to enable SOF/ITP counter
* running based on ref_clk
* @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
+ * @filter_se0_fsls_eop_quirk: set to ignores single
+ * SE0 glitch on the linestate during transmit.
* @tx_de_emphasis: Tx de-emphasis value
* 0 - -6dB de-emphasis
* 1 - -3.5dB de-emphasis
@@ -1373,6 +1376,7 @@ struct dwc3 {
unsigned gfladj_refclk_lpm_sel:1;
unsigned tx_de_emphasis_quirk:1;
+ unsigned filter_se0_fsls_eop_quirk:1;
unsigned tx_de_emphasis:2;
unsigned dis_metastability_quirk:1;
Thanks,
Akash
Hi Akash,
Apologies for a late reply.
About device mode use case of this bit, there is the possibility that a
device may enter L1 earlier than
the Host LPM Retry Time in the case when a device ACK handshake is
dropped due to errors.
Thus, this bit is not normally required to be set in device mode.
Thanks,
Uttkarsh
