gpu: ipu-v3: prg: avoid possible array underflow

gcc-8 reports that we access an array with a negative index
in an error case:

drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable':
drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds]

This moves the range check in front of the first time that
variable gets used.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
This commit is contained in:
Arnd Bergmann 2018-03-15 17:19:57 +01:00 committed by Philipp Zabel
parent 0c8efd610b
commit 746d024c32

View File

@ -250,10 +250,14 @@ void ipu_prg_channel_disable(struct ipuv3_channel *ipu_chan)
{ {
int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num);
struct ipu_prg *prg = ipu_chan->ipu->prg_priv; struct ipu_prg *prg = ipu_chan->ipu->prg_priv;
struct ipu_prg_channel *chan = &prg->chan[prg_chan]; struct ipu_prg_channel *chan;
u32 val; u32 val;
if (!chan->enabled || prg_chan < 0) if (prg_chan < 0)
return;
chan = &prg->chan[prg_chan];
if (!chan->enabled)
return; return;
pm_runtime_get_sync(prg->dev); pm_runtime_get_sync(prg->dev);
@ -280,13 +284,15 @@ int ipu_prg_channel_configure(struct ipuv3_channel *ipu_chan,
{ {
int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num);
struct ipu_prg *prg = ipu_chan->ipu->prg_priv; struct ipu_prg *prg = ipu_chan->ipu->prg_priv;
struct ipu_prg_channel *chan = &prg->chan[prg_chan]; struct ipu_prg_channel *chan;
u32 val; u32 val;
int ret; int ret;
if (prg_chan < 0) if (prg_chan < 0)
return prg_chan; return prg_chan;
chan = &prg->chan[prg_chan];
if (chan->enabled) { if (chan->enabled) {
ipu_pre_update(prg->pres[chan->used_pre], *eba); ipu_pre_update(prg->pres[chan->used_pre], *eba);
return 0; return 0;