diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2016-09-30 18:19:01 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2016-09-30 23:16:35 +0530 |
| commit | 2cc40ee7ae30fa12c3ee3f18e6c0e81cced2cdcc (patch) | |
| tree | 4c7b6b93bf9f3447c839d2266e8f97b2ce60628c /drivers/dma/edma.c | |
| parent | 3a03ea763a675ecb2a8805c6db01af125daa56e4 (diff) | |
dmaengine: edma: avoid uninitialized variable use
If edma_read_slot() gets an invalid argument, it does not set a result,
as found by "gcc -Wmaybe-uninitialized"
drivers/dma/edma.c: In function 'dma_ccerr_handler':
drivers/dma/edma.c:1499:21: error: 'p.a_b_cnt' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/dma/edma.c:1499:21: error: 'p.ccnt' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (p.a_b_cnt == 0 && p.ccnt == 0) {
If we change the function to return an error in this case, we can handle
the failure more gracefully and treat this the same way as a null slot
that we already catch.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/edma.c')
| -rw-r--r-- | drivers/dma/edma.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 3d277fa76c1a..9d5dff4a43fd 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -464,13 +464,15 @@ static void edma_write_slot(struct edma_cc *ecc, unsigned slot, memcpy_toio(ecc->base + PARM_OFFSET(slot), param, PARM_SIZE); } -static void edma_read_slot(struct edma_cc *ecc, unsigned slot, +static int edma_read_slot(struct edma_cc *ecc, unsigned slot, struct edmacc_param *param) { slot = EDMA_CHAN_SLOT(slot); if (slot >= ecc->num_slots) - return; + return -EINVAL; memcpy_fromio(param, ecc->base + PARM_OFFSET(slot), PARM_SIZE); + + return 0; } /** @@ -1476,13 +1478,15 @@ static void edma_error_handler(struct edma_chan *echan) struct edma_cc *ecc = echan->ecc; struct device *dev = echan->vchan.chan.device->dev; struct edmacc_param p; + int err; if (!echan->edesc) return; spin_lock(&echan->vchan.lock); - edma_read_slot(ecc, echan->slot[0], &p); + err = edma_read_slot(ecc, echan->slot[0], &p); + /* * Issue later based on missed flag which will be sure * to happen as: @@ -1495,7 +1499,7 @@ static void edma_error_handler(struct edma_chan *echan) * lead to some nasty recursion when we are in a NULL * slot. So we avoid doing so and set the missed flag. */ - if (p.a_b_cnt == 0 && p.ccnt == 0) { + if (err || (p.a_b_cnt == 0 && p.ccnt == 0)) { dev_dbg(dev, "Error on null slot, setting miss\n"); echan->missed = 1; } else { |