diff options
| author | Pawel Laszczak <pawell@cadence.com> | 2021-09-07 08:26:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-14 10:32:41 +0200 |
| commit | b69ec50b3e55c4b2a85c8bc46763eaf330605847 (patch) | |
| tree | 34db91b982bec653060f528574ab7c740dfd1708 /drivers/usb/cdns3 | |
| parent | 17956b53ebff6a490baf580a836cbd3eae94892b (diff) | |
| download | linux-b69ec50b3e55c4b2a85c8bc46763eaf330605847.tar.bz2 | |
usb: cdns3: fix race condition before setting doorbell
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
Tested-by: Aswath Govindraju <a-govindraju@ti.com>
Reviewed-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Link: https://lore.kernel.org/r/20210907062619.34622-1-pawell@gli-login.cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/cdns3')
| -rw-r--r-- | drivers/usb/cdns3/cdns3-gadget.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 5d8c982019af..1f3b4a142212 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)); } |