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| author | Felipe Balbi <balbi@ti.com> | 2012-09-18 21:39:24 +0300 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2013-03-18 11:17:57 +0200 |
| commit | 0b0cc1cd31bed3e3147398e54530f1f819b27692 (patch) | |
| tree | fefac187ba34d39b4116c9e71ff5289188c65747 /drivers | |
| parent | 7ac6a593d512de38e710591afea4c839626b3bd0 (diff) | |
| download | linux-0b0cc1cd31bed3e3147398e54530f1f819b27692.tar.gz linux-0b0cc1cd31bed3e3147398e54530f1f819b27692.tar.bz2 linux-0b0cc1cd31bed3e3147398e54530f1f819b27692.zip | |
usb: dwc3: workaround: unexpected transtion U3 -> RESUME
In DWC3 versions < 2.50a configured without
Hibernation mode enabled, there will be an
extra link status change interrupt if device
detects host-initiated U3 exit.
In that case, core will generate an unnecessary
U3 -> RESUME transition which should be ignored
by the driver.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 4ffec1aa2e25..8e53acc0e43e 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2317,6 +2317,34 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc, unsigned int evtinfo) { enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK; + unsigned int pwropt; + + /* + * WORKAROUND: DWC3 < 2.50a have an issue when configured without + * Hibernation mode enabled which would show up when device detects + * host-initiated U3 exit. + * + * In that case, device will generate a Link State Change Interrupt + * from U3 to RESUME which is only necessary if Hibernation is + * configured in. + * + * There are no functional changes due to such spurious event and we + * just need to ignore it. + * + * Refers to: + * + * STAR#9000570034 RTL: SS Resume event generated in non-Hibernation + * operational mode + */ + pwropt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1); + if ((dwc->revision < DWC3_REVISION_250A) && + (pwropt != DWC3_GHWPARAMS1_EN_PWROPT_HIB)) { + if ((dwc->link_state == DWC3_LINK_STATE_U3) && + (next == DWC3_LINK_STATE_RESUME)) { + dev_vdbg(dwc->dev, "ignoring transition U3 -> Resume\n"); + return; + } + } /* * WORKAROUND: DWC3 Revisions <1.83a have an issue which, depending |