[PATCH 5.12 121/384] usb: dwc3: gadget: Check for disabled LPM quirk

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 08:16:36 EST


From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

[ Upstream commit 475e8be53d0496f9bc6159f4abb3ff5f9b90e8de ]

If the device doesn't support LPM, make sure to disable the LPM
capability and don't advertise to the host that it supports it.

Acked-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/9e68527ff932b1646f92a7593d4092a903754666.1618366071.git.Thinh.Nguyen@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 2 ++
drivers/usb/dwc3/core.h | 4 +++-
drivers/usb/dwc3/gadget.c | 9 ++++++++-
3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index f2448d0a9d39..b46985c9595f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1277,6 +1277,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
"snps,usb3_lpm_capable");
dwc->usb2_lpm_disable = device_property_read_bool(dev,
"snps,usb2-lpm-disable");
+ dwc->usb2_gadget_lpm_disable = device_property_read_bool(dev,
+ "snps,usb2-gadget-lpm-disable");
device_property_read_u8(dev, "snps,rx-thr-num-pkt-prd",
&rx_thr_num_pkt_prd);
device_property_read_u8(dev, "snps,rx-max-burst-prd",
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 052b20d52651..7ae6684a94ae 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1034,7 +1034,8 @@ struct dwc3_scratchpad_array {
* @dis_start_transfer_quirk: set if start_transfer failure SW workaround is
* not needed for DWC_usb31 version 1.70a-ea06 and below
* @usb3_lpm_capable: set if hadrware supports Link Power Management
- * @usb2_lpm_disable: set to disable usb2 lpm
+ * @usb2_lpm_disable: set to disable usb2 lpm for host
+ * @usb2_gadget_lpm_disable: set to disable usb2 lpm for gadget
* @disable_scramble_quirk: set if we enable the disable scramble quirk
* @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
* @u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
@@ -1238,6 +1239,7 @@ struct dwc3 {
unsigned dis_start_transfer_quirk:1;
unsigned usb3_lpm_capable:1;
unsigned usb2_lpm_disable:1;
+ unsigned usb2_gadget_lpm_disable:1;

unsigned disable_scramble_quirk:1;
unsigned u2exit_lfps_quirk:1;
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 111ab6f6c055..41bb75a3abe5 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3469,6 +3469,7 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
/* Enable USB2 LPM Capability */

if (!DWC3_VER_IS_WITHIN(DWC3, ANY, 194A) &&
+ !dwc->usb2_gadget_lpm_disable &&
(speed != DWC3_DSTS_SUPERSPEED) &&
(speed != DWC3_DSTS_SUPERSPEED_PLUS)) {
reg = dwc3_readl(dwc->regs, DWC3_DCFG);
@@ -3495,6 +3496,12 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)

dwc3_gadget_dctl_write_safe(dwc, reg);
} else {
+ if (dwc->usb2_gadget_lpm_disable) {
+ reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+ reg &= ~DWC3_DCFG_LPM_CAP;
+ dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+ }
+
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
reg &= ~DWC3_DCTL_HIRD_THRES_MASK;
dwc3_gadget_dctl_write_safe(dwc, reg);
@@ -3943,7 +3950,7 @@ int dwc3_gadget_init(struct dwc3 *dwc)
dwc->gadget->ssp_rate = USB_SSP_GEN_UNKNOWN;
dwc->gadget->sg_supported = true;
dwc->gadget->name = "dwc3-gadget";
- dwc->gadget->lpm_capable = true;
+ dwc->gadget->lpm_capable = !dwc->usb2_gadget_lpm_disable;

/*
* FIXME We might be setting max_speed to <SUPER, however versions
--
2.30.2