From 424103642d009f5a7dc33300a49d5606d1bf4fb5 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:03 +0000 Subject: [PATCH] dmaengine: add dma_device_get() helper Add dma_device_get() helper to match dma_device_put() to make code symmetric. It wraps open-coded kref_get_unless_zero() and asserts that dma_list_mutex is held, matching its put counterpart. No functional change intended. Suggested-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-1-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 6ffd8bd82154..6b8af8607e5c 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -433,6 +433,12 @@ static void dma_device_release(struct kref *ref) device->device_release(device); } +static int __must_check dma_device_get(struct dma_device *device) +{ + lockdep_assert_held(&dma_list_mutex); + return kref_get_unless_zero(&device->ref); +} + static void dma_device_put(struct dma_device *device) { lockdep_assert_held(&dma_list_mutex); @@ -460,8 +466,7 @@ static int dma_chan_get(struct dma_chan *chan) if (!try_module_get(owner)) return -ENODEV; - ret = kref_get_unless_zero(&chan->device->ref); - if (!ret) { + if (!dma_device_get(chan->device)) { ret = -ENODEV; goto module_put_out; }