The driver may sleep with holding a spinlock. The function call path (from bottom to top) in Linux-4.17 is: [FUNC] usleep_range drivers/staging/dgnc/dgnc_cls.c, 391: usleep_range in cls_assert_modem_signals drivers/staging/dgnc/dgnc_cls.c, 449: cls_assert_modem_signals in cls_copy_data_from_queue_to_uart drivers/staging/dgnc/dgnc_cls.c, 406: _raw_spin_lock_irqsave in cls_copy_data_from_queue_to_uart To fix this bug, usleep_range() is replaced with udelay(). This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> --- drivers/staging/dgnc/dgnc_cls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/dgnc/dgnc_cls.c b/drivers/staging/dgnc/dgnc_cls.c index 7e6cbfe4e4ee..a1e98ee7f9e0 100644 --- a/drivers/staging/dgnc/dgnc_cls.c +++ b/drivers/staging/dgnc/dgnc_cls.c @@ -388,7 +388,7 @@ static void cls_assert_modem_signals(struct channel_t *ch) writeb(out, &ch->ch_cls_uart->mcr); /* Give time for the UART to actually drop the signals */ - usleep_range(10, 20); + udelay(20); } static void cls_copy_data_from_queue_to_uart(struct channel_t *ch) -- 2.17.0 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
