diff options
| author | Rohith Kollalsi <quic_rkollals@quicinc.com> | 2022-07-14 07:56:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-14 17:10:30 +0300 |
| commit | 07903626d98853e605fe63e5ce149f1b7314bbea (patch) | |
| tree | ba3f577572a80e6869de47c20c193502563f206a /drivers/usb | |
| parent | 220fafb4ed04187e9c17be4152da5a7f2ffbdd8c (diff) | |
| download | linux-07903626d98853e605fe63e5ce149f1b7314bbea.tar.xz | |
usb: dwc3: core: Do not perform GCTL_CORE_SOFTRESET during bootup
According to the programming guide, it is recommended to
perform a GCTL_CORE_SOFTRESET only when switching the mode
from device to host or host to device. However, it is found
that during bootup when __dwc3_set_mode() is called for the
first time, GCTL_CORESOFTRESET is done with suspendable bit(BIT 17)
of DWC3_GUSB3PIPECTL set. This some times leads to issues
like controller going into bad state and controller registers
reading value zero. Until GCTL_CORESOFTRESET is done and
run/stop bit is set core initialization is not complete.
Setting suspendable bit of DWC3_GUSB3PIPECTL and then
performing GCTL_CORESOFTRESET is therefore not recommended.
Avoid this by only performing the reset if current_dr_role is set,
that is, when doing subsequent role switching.
Fixes: f88359e1588b ("usb: dwc3: core: Do core softreset when switch mode")
Signed-off-by: Rohith Kollalsi <quic_rkollals@quicinc.com>
Link: https://lore.kernel.org/r/20220714045625.20377-1-quic_rkollals@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/dwc3/core.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 050b2ba5986d..c5c238ab3083 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -158,9 +158,13 @@ static void __dwc3_set_mode(struct work_struct *work) break; } - /* For DRD host or device mode only */ - if ((DWC3_IP_IS(DWC3) || DWC3_VER_IS_PRIOR(DWC31, 190A)) && - dwc->desired_dr_role != DWC3_GCTL_PRTCAP_OTG) { + /* + * When current_dr_role is not set, there's no role switching. + * Only perform GCTL.CoreSoftReset when there's DRD role switching. + */ + if (dwc->current_dr_role && ((DWC3_IP_IS(DWC3) || + DWC3_VER_IS_PRIOR(DWC31, 190A)) && + dwc->desired_dr_role != DWC3_GCTL_PRTCAP_OTG)) { reg = dwc3_readl(dwc->regs, DWC3_GCTL); reg |= DWC3_GCTL_CORESOFTRESET; dwc3_writel(dwc->regs, DWC3_GCTL, reg); |