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authorTudor Ambarus <tudor.ambarus@microchip.com>2020-01-23 17:03:06 +0300
committerVinod Koul <vkoul@kernel.org>2020-02-25 08:57:27 +0300
commitad16bc232dd72f85984c790e07c69009b7c850c8 (patch)
tree5bbe4d155f66038df71ac4f10309e776816cafbe /drivers/dma/at_hdmac.c
parentbbc58394d81110f76586d3053fd5a3a3ad616050 (diff)
downloadlinux-ad16bc232dd72f85984c790e07c69009b7c850c8.tar.xz
dmaengine: at_hdmac: Return err in case the chan is not free at alloc res time
Having a list of descriptors allocated for the channel at device_alloc_chan_resources() time is a sign for bad free usage. Return err and add a debug message in case the channel is not free from a previous use. atchan->descs_allocated becomes useless, get rid of it. More, drop the error message in atc_desc_get() because now it would introduce an extra if statement. The callers of atc_desc_get() already print error messages in case the callee fails, no one is hurt. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-3-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/at_hdmac.c')
-rw-r--r--drivers/dma/at_hdmac.c31
1 files changed, 8 insertions, 23 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 301bae45cf8d..e17b75075904 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -146,17 +146,8 @@ static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
"scanned %u descriptors on freelist\n", i);
/* no more descriptor available in initial pool: create one more */
- if (!ret) {
+ if (!ret)
ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
- if (ret) {
- spin_lock_irqsave(&atchan->lock, flags);
- atchan->descs_allocated++;
- spin_unlock_irqrestore(&atchan->lock, flags);
- } else {
- dev_err(chan2dev(&atchan->chan_common),
- "not enough descriptors available\n");
- }
- }
return ret;
}
@@ -1553,6 +1544,11 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
return -EIO;
}
+ if (!list_empty(&atchan->free_list)) {
+ dev_dbg(chan2dev(chan), "can't allocate channel resources (channel not freed from a previous use)\n");
+ return -EIO;
+ }
+
cfg = ATC_DEFAULT_CFG;
atslave = chan->private;
@@ -1568,11 +1564,6 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
cfg = atslave->cfg;
}
- /* have we already been set up?
- * reconfigure channel but no need to reallocate descriptors */
- if (!list_empty(&atchan->free_list))
- return atchan->descs_allocated;
-
/* Allocate initial pool of descriptors */
for (i = 0; i < init_nr_desc_per_channel; i++) {
desc = atc_alloc_descriptor(chan, GFP_KERNEL);
@@ -1584,17 +1575,15 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
list_add_tail(&desc->desc_node, &atchan->free_list);
}
- atchan->descs_allocated = i;
dma_cookie_init(chan);
/* channel parameters */
channel_writel(atchan, CFG, cfg);
dev_dbg(chan2dev(chan),
- "alloc_chan_resources: allocated %d descriptors\n",
- atchan->descs_allocated);
+ "alloc_chan_resources: allocated %d descriptors\n", i);
- return atchan->descs_allocated;
+ return i;
}
/**
@@ -1608,9 +1597,6 @@ static void atc_free_chan_resources(struct dma_chan *chan)
struct at_desc *desc, *_desc;
LIST_HEAD(list);
- dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n",
- atchan->descs_allocated);
-
/* ASSERT: channel is idle */
BUG_ON(!list_empty(&atchan->active_list));
BUG_ON(!list_empty(&atchan->queue));
@@ -1623,7 +1609,6 @@ static void atc_free_chan_resources(struct dma_chan *chan)
dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
}
list_splice_init(&atchan->free_list, &list);
- atchan->descs_allocated = 0;
atchan->status = 0;
/*