| Message ID | 20210907062619.34622-1-pawell@gli-login.cadence.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | b69ec50b3e55c4b2a85c8bc46763eaf330605847 |
| Headers | show |
| Series | usb: cdns3: fix race condition before setting doorbell | expand |
On 07/09/21 11:56 am, Pawel Laszczak wrote: > From: Pawel Laszczak <pawell@cadence.com> > > For DEV_VER_V3 version there exist race condition between clearing > ep_sts.EP_STS_TRBERR and setting ep_cmd.EP_CMD_DRDY bit. > Setting EP_CMD_DRDY will be ignored by controller when > EP_STS_TRBERR is set. So, between these two instructions we have > a small time gap in which the EP_STSS_TRBERR can be set. In such case > the transfer will not start after setting doorbell. > > Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") > cc: <stable@vger.kernel.org> # 5.12.x > Signed-off-by: Pawel Laszczak <pawell@cadence.com> > --- Reviewed-by: Aswath Govindraju <a-govindraju@ti.com> Tested-by: Aswath Govindraju <a-govindraju@ti.com> > drivers/usb/cdns3/cdns3-gadget.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c > index 80aaab159e58..e9769fab21ea 100644 > --- a/drivers/usb/cdns3/cdns3-gadget.c > +++ b/drivers/usb/cdns3/cdns3-gadget.c > @@ -1100,6 +1100,19 @@ static int cdns3_ep_run_stream_transfer(struct cdns3_endpoint *priv_ep, > return 0; > } > > +static void cdns3_rearm_drdy_if_needed(struct cdns3_endpoint *priv_ep) > +{ > + struct cdns3_device *priv_dev = priv_ep->cdns3_dev; > + > + if (priv_dev->dev_ver < DEV_VER_V3) > + return; > + > + if (readl(&priv_dev->regs->ep_sts) & EP_STS_TRBERR) { > + writel(EP_STS_TRBERR, &priv_dev->regs->ep_sts); > + writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); > + } > +} > + > /** > * cdns3_ep_run_transfer - start transfer on no-default endpoint hardware > * @priv_ep: endpoint object > @@ -1351,6 +1364,7 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, > /*clearing TRBERR and EP_STS_DESCMIS before seting DRDY*/ > writel(EP_STS_TRBERR | EP_STS_DESCMIS, &priv_dev->regs->ep_sts); > writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); > + cdns3_rearm_drdy_if_needed(priv_ep); > trace_cdns3_doorbell_epx(priv_ep->name, > readl(&priv_dev->regs->ep_traddr)); > } >
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 80aaab159e58..e9769fab21ea 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1100,6 +1100,19 @@ static int cdns3_ep_run_stream_transfer(struct cdns3_endpoint *priv_ep, return 0; } +static void cdns3_rearm_drdy_if_needed(struct cdns3_endpoint *priv_ep) +{ + struct cdns3_device *priv_dev = priv_ep->cdns3_dev; + + if (priv_dev->dev_ver < DEV_VER_V3) + return; + + if (readl(&priv_dev->regs->ep_sts) & EP_STS_TRBERR) { + writel(EP_STS_TRBERR, &priv_dev->regs->ep_sts); + writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); + } +} + /** * cdns3_ep_run_transfer - start transfer on no-default endpoint hardware * @priv_ep: endpoint object @@ -1351,6 +1364,7 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, /*clearing TRBERR and EP_STS_DESCMIS before seting DRDY*/ writel(EP_STS_TRBERR | EP_STS_DESCMIS, &priv_dev->regs->ep_sts); writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); + cdns3_rearm_drdy_if_needed(priv_ep); trace_cdns3_doorbell_epx(priv_ep->name, readl(&priv_dev->regs->ep_traddr)); }