From: patrice.chotard@st.com (Patrice Chotard) Date: Mon, 7 Mar 2016 09:16:25 +0100 Subject: [PATCH 4/6] [media] st-rc: prevent a endless loop In-Reply-To: <087329695244e466f0c2d9a3a58e10ad399cd674.1457271549.git.mchehab@osg.samsung.com> References: <076989c7736719982a1bc9557d7db072910d8efe.1457271549.git.mchehab@osg.samsung.com> <087329695244e466f0c2d9a3a58e10ad399cd674.1457271549.git.mchehab@osg.samsung.com> Message-ID: <56DD38D9.20002@st.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Mauro On 03/06/2016 02:39 PM, Mauro Carvalho Chehab wrote: > As warned by smatch: > drivers/media/rc/st_rc.c:110 st_rc_rx_interrupt() warn: this loop depends on readl() succeeding > > as readl() might fail, with likely means some unrecovered error, > let's loop only if it succeeds. > > Signed-off-by: Mauro Carvalho Chehab > --- > drivers/media/rc/st_rc.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c > index 1fa0c9d1c508..151bfe2aea55 100644 > --- a/drivers/media/rc/st_rc.c > +++ b/drivers/media/rc/st_rc.c > @@ -99,7 +99,7 @@ static irqreturn_t st_rc_rx_interrupt(int irq, void *data) > unsigned int symbol, mark = 0; > struct st_rc_device *dev = data; > int last_symbol = 0; > - u32 status; > + int status; > DEFINE_IR_RAW_EVENT(ev); > > if (dev->irq_wake) > @@ -107,7 +107,7 @@ static irqreturn_t st_rc_rx_interrupt(int irq, void *data) > > status = readl(dev->rx_base + IRB_RX_STATUS); > > - while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) { > + while (status > 0 && (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW))) { > u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS); > if (unlikely(int_status & IRB_RX_OVERRUN_INT)) { > /* discard the entire collection in case of errors! */ Acked-by: Patrice Chotard