diff options
| author |   Tudor Ambarus <tudor.ambarus@microchip.com> | 2020-01-23 14:03:06 +0000 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2020-02-25 11:27:27 +0530 |
| commit | ad16bc232dd72f85984c790e07c69009b7c850c8 (patch) | |
| tree | 5bbe4d155f66038df71ac4f10309e776816cafbe /drivers/dma/at_hdmac.c | |
| parent | dmaengine: at_hdmac: Drop locking in at_hdmac_alloc_chan_resources() (diff) | |
| download | linux-dev-ad16bc232dd72f85984c790e07c69009b7c850c8.tar.xz linux-dev-ad16bc232dd72f85984c790e07c69009b7c850c8.zip | |
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.c | 31 |
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; /* |