From: Dan Carpenter <dan.carpenter@oracle.com>
To: chunfeng.yun@mediatek.com
Cc: linux-usb@vger.kernel.org
Subject: [bug report] usb: gadget: bdc: use readl_poll_timeout() to simplify code
Date: Tue, 27 Jul 2021 11:42:08 +0300 [thread overview]
Message-ID: <20210727084208.GA19962@kili> (raw)
Hello Chunfeng Yun,
The patch 75ae051efc9b: "usb: gadget: bdc: use readl_poll_timeout()
to simplify code" from Jul 13, 2020, leads to the following static
checker warning:
drivers/usb/gadget/udc/bdc/bdc_core.c:38 poll_oip()
warn: sleeping in atomic context
drivers/usb/gadget/udc/bdc/bdc_core.c
33 static int poll_oip(struct bdc *bdc, u32 usec)
34 {
35 u32 status;
36 int ret;
37
--> 38 ret = readl_poll_timeout(bdc->regs + BDC_BDCSC, status,
39 (BDC_CSTS(status) != BDC_OIP), 10, usec);
^^
This adds a 10us sleep, but we're holding a spin lock so it's a sleeping
in atomic bug. One call tree is:
bdc_udc_stop() <-- takes a spin lock
--> bdc_stop
--> poll_oip() <-- sleep
40 if (ret)
41 dev_err(bdc->dev, "operation timedout BDCSC: 0x%08x\n", status);
42 else
43 dev_dbg(bdc->dev, "%s complete status=%d", __func__, BDC_CSTS(status));
44
45 return ret;
46 }
regards,
dan carpenter
reply other threads:[~2021-07-27 8:42 UTC|newest]
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