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)); }