2022-09-01 14:52:20

by Koba Ko

Subject: [PATCH V3] crypto: ccp - Release dma channels before dmaengine unrgister

A warning is shown during shutdown,

__dma_async_device_channel_unregister called while 2 clients hold a reference
WARNING: CPU: 15 PID: 1 at drivers/dma/dmaengine.c:1110 __dma_async_device_channel_unregister+0xb7/0xc0

Call dma_release_channel for occupied channles before dma_async_device_unregister.

Fixes: 54cce8ecb925 ("crypto: ccp - ccp_dmaengine_unregister release dma channels")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Koba Ko <[email protected]>
Acked-by: Tom Lendacky <[email protected]>

---
V2: Fix the unused warning
V3: Fix the Fixes: tag.
---
drivers/crypto/ccp/ccp-dmaengine.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index 7d4b4ad1db1f3..9f753cb4f5f18 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -641,6 +641,10 @@ static void ccp_dma_release(struct ccp_device *ccp)
for (i = 0; i < ccp->cmd_q_count; i++) {
chan = ccp->ccp_dma_chan + i;
dma_chan = &chan->dma_chan;
+
+ if (dma_chan->client_count)
+ dma_release_channel(dma_chan);
+
tasklet_kill(&chan->cleanup_tasklet);
list_del_rcu(&dma_chan->device_node);
}
@@ -766,8 +770,8 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
if (!dmaengine)
return;

- dma_async_device_unregister(dma_dev);
ccp_dma_release(ccp);
+ dma_async_device_unregister(dma_dev);

kmem_cache_destroy(ccp->dma_desc_cache);
kmem_cache_destroy(ccp->dma_cmd_cache);
--
2.25.1

2022-09-09 09:09:55

by Herbert Xu

Subject: Re: [PATCH V3] crypto: ccp - Release dma channels before dmaengine unrgister

On Thu, Sep 01, 2022 at 10:47:12PM +0800, Koba Ko wrote:
> A warning is shown during shutdown,
>
> __dma_async_device_channel_unregister called while 2 clients hold a reference
> WARNING: CPU: 15 PID: 1 at drivers/dma/dmaengine.c:1110 __dma_async_device_channel_unregister+0xb7/0xc0
>
> Call dma_release_channel for occupied channles before dma_async_device_unregister.
>
> Fixes: 54cce8ecb925 ("crypto: ccp - ccp_dmaengine_unregister release dma channels")
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Koba Ko <[email protected]>
> Acked-by: Tom Lendacky <[email protected]>
>
> ---
> V2: Fix the unused warning
> V3: Fix the Fixes: tag.
> ---
> drivers/crypto/ccp/ccp-dmaengine.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt