[PATCH AUTOSEL 5.15 32/47] usb: dwc3: core: Enable GUCTL1 bit 10 for fixing termination error after resume bug

Sasha Levin
2022-10-13T00:29:50Z

From: Piyush Mehta <piyush.mehta@amd.com>

[ Upstream commit 63d7f9810a38102cdb8cad214fac98682081e1a7 ]

When configured in HOST mode, after issuing U3/L2 exit controller fails
to send proper CRC checksum in CRC5 field. Because of this behavior
Transaction Error is generated, resulting in reset and re-enumeration of
usb device attached. Enabling chicken bit 10 of GUCTL1 will correct this
problem.

When this bit is set to '1', the UTMI/ULPI opmode will be changed to
"normal" along with HS terminations, term, and xcvr signals after EOR.
This option is to support certain legacy UTMI/ULPI PHYs.

Added "snps,resume-hs-terminations" quirk to resolved the above issue.

Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
Link: https://lore.kernel.org/r/20220920052235.194272-3-piyush.mehta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/dwc3/core.c | 17 +++++++++++++++++
drivers/usb/dwc3/core.h | 4 ++++
2 files changed, 21 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c32ca691bcc7..a2f3e56aba05 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1041,6 +1041,21 @@ static int dwc3_core_init(struct dwc3 *dwc)
dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
}

+ /*
+ * When configured in HOST mode, after issuing U3/L2 exit controller
+ * fails to send proper CRC checksum in CRC5 feild. Because of this
+ * behaviour Transaction Error is generated, resulting in reset and
+ * re-enumeration of usb device attached. All the termsel, xcvrsel,
+ * opmode becomes 0 during end of resume. Enabling bit 10 of GUCTL1
+ * will correct this problem. This option is to support certain
+ * legacy ULPI PHYs.
+ */
+ if (dwc->resume_hs_terminations) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
+ reg |= DWC3_GUCTL1_RESUME_OPMODE_HS_HOST;
+ dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
+ }
+
if (!DWC3_VER_IS_PRIOR(DWC3, 250A)) {
reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);

@@ -1383,6 +1398,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
"snps,dis-del-phy-power-chg-quirk");
dwc->dis_tx_ipgap_linecheck_quirk = device_property_read_bool(dev,
"snps,dis-tx-ipgap-linecheck-quirk");
+ dwc->resume_hs_terminations = device_property_read_bool(dev,
+ "snps,resume-hs-terminations");
dwc->parkmode_disable_ss_quirk = device_property_read_bool(dev,
"snps,parkmode-disable-ss-quirk");

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 077d03a33388..e82e4cbe4ec7 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -260,6 +260,7 @@
#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
#define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
#define DWC3_GUCTL1_PARKMODE_DISABLE_SS BIT(17)
+#define DWC3_GUCTL1_RESUME_OPMODE_HS_HOST BIT(10)

/* Global Status Register */
#define DWC3_GSTS_OTG_IP BIT(10)
@@ -1072,6 +1073,8 @@ struct dwc3_scratchpad_array {
* change quirk.
* @dis_tx_ipgap_linecheck_quirk: set if we disable u2mac linestate
* check during HS transmit.
+ * @resume-hs-terminations: Set if we enable quirk for fixing improper crc
+ * generation after resume from suspend.
* @parkmode_disable_ss_quirk: set if we need to disable all SuperSpeed
* instances in park mode.
* @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
@@ -1284,6 +1287,7 @@ struct dwc3 {
unsigned dis_u2_freeclk_exists_quirk:1;
unsigned dis_del_phy_power_chg_quirk:1;
unsigned dis_tx_ipgap_linecheck_quirk:1;
+ unsigned resume_hs_terminations:1;
unsigned parkmode_disable_ss_quirk:1;

unsigned tx_de_emphasis_quirk:1;
--
2.35.1