From: "Anton D. Stavinskii" <stavinsky@gmail.com>
To: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
inochiama@gmail.com, "Anton D. Stavinskii" <stavinsky@gmail.com>
Subject: [PATCH] dmaengine: cv1800b-dmamux: fix channel allocation order
Date: Wed, 10 Dec 2025 23:30:12 +0400 [thread overview]
Message-ID: <20251210193011.567210-2-stavinsky@gmail.com> (raw)
The dmamux builds the free_maps list using llist_add(), which inserts
new nodes at the head. Using increasing channel indices causes the
first allocation to use DMA channel 7 while the DMA engine hands out
channel 0, leading to mismatched routing.
Reverse the channel index order so the first allocation gets channel 0.
Fixes: db7d07b5add4d ("dmaengine: add driver for Sophgo CV18XX/SG200X dmamux")
Signed-off-by: Anton D. Stavinskii <stavinsky@gmail.com>
---
drivers/dma/cv1800b-dmamux.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/cv1800b-dmamux.c b/drivers/dma/cv1800b-dmamux.c
index e900d6595617..825e1614051d 100644
--- a/drivers/dma/cv1800b-dmamux.c
+++ b/drivers/dma/cv1800b-dmamux.c
@@ -214,7 +214,7 @@ static int cv1800_dmamux_probe(struct platform_device *pdev)
}
init_llist_node(&tmp->node);
- tmp->channel = i;
+ tmp->channel = MAX_DMA_CH_ID - i;
llist_add(&tmp->node, &data->free_maps);
}
--
2.43.0
next reply other threads:[~2025-12-10 19:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-10 19:30 Anton D. Stavinskii [this message]
2025-12-12 2:12 ` [PATCH] dmaengine: cv1800b-dmamux: fix channel allocation order Inochi Amaoto
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