[PATCH v3 04/59] dmaengine: Rework dma_chan_get
From: Maxime Ripard <hidden>
Date: 2014-10-22 16:13:13
Also in:
lkml
Subsystem:
dma generic offload engine subsystem, the rest · Maintainers:
Vinod Koul, Linus Torvalds
dma_chan_get uses a rather interesting error handling and code path. Change it to something more usual in the kernel. Signed-off-by: Maxime Ripard <redacted> --- drivers/dma/dmaengine.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 24bfaf0b92ba..72f10e2f5c32 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c@@ -222,31 +222,33 @@ static void balance_ref_count(struct dma_chan *chan) */ static int dma_chan_get(struct dma_chan *chan) { - int err = -ENODEV; struct module *owner = dma_chan_to_owner(chan); + int ret; + /* The channel is already in use, update client count */ if (chan->client_count) { __module_get(owner); - err = 0; - } else if (try_module_get(owner)) - err = 0; + goto out; + } - if (err == 0) - chan->client_count++; + if (!try_module_get(owner)) + return -ENODEV; /* allocate upon first client reference */ - if (chan->client_count == 1 && err == 0) { - int desc_cnt = chan->device->device_alloc_chan_resources(chan); - - if (desc_cnt < 0) { - err = desc_cnt; - chan->client_count = 0; - module_put(owner); - } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask)) - balance_ref_count(chan); - } + ret = chan->device->device_alloc_chan_resources(chan); + if (ret < 0) + goto err_out; - return err; + if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask)) + balance_ref_count(chan); + +out: + chan->client_count++; + return 0; + +err_out: + module_put(owner); + return ret; } /**
--
2.1.1