Hello Fuqian Huang,
The patch b65dc4f6b339: "mfd: ezx-pcap: Replace mutex_lock with
spin_lock" from Aug 13, 2019 (linux-next), leads to the following
Smatch static checker warning:
drivers/mfd/ezx-pcap.c:102 ezx_pcap_read() warn: sleeping in atomic context
drivers/mfd/ezx-pcap.c:102 ezx_pcap_read() warn: sleeping in IRQ context
drivers/mfd/ezx-pcap.c
93 int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
94 {
95 unsigned long flags;
96 int ret;
97
98 spin_lock_irqsave(&pcap->io_lock, flags);
^^^^^^^^^^^^^^^^^^
Taking a spinlock.
99 *value = PCAP_REGISTER_READ_OP_BIT
100 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
101
--> 102 ret = ezx_pcap_putget(pcap, value);
My static checker agrees with you that this is an IRQ function but the
ezx_pcap_putget() function takes a mutex and we can't do that from an
IRQ function.
103 spin_unlock_irqrestore(&pcap->io_lock, flags);
104
105 return ret;
106 }
regards,
dan carpenter
