On Fri, Mar 27, 2015 at 03:06:27PM +0800, Li Jun wrote: > Since the required clock to access registers is gated off in low power mode, > add ci->in_lpm check before try to dump registers value. > > Signed-off-by: Li Jun <jun.li@xxxxxxxxxxxxx> > --- > drivers/usb/chipidea/debug.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c > index 268e423..a367cee 100644 > --- a/drivers/usb/chipidea/debug.c > +++ b/drivers/usb/chipidea/debug.c > @@ -339,6 +339,11 @@ static int ci_registers_show(struct seq_file *s, void *unused) > if (!ci) > return 0; > > + if (ci->in_lpm) { > + seq_printf(s, "Can't dump registers value in low power mode\n"); > + return 0; > + } > + > /* ------ Registers ----- */ > tmp_reg = hw_read_intr_enable(ci); > seq_printf(s, "USBINTR reg: %08x\n", tmp_reg); > -- > 1.9.1 > Why not just return error code, it will show warning message too. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html