[PATCH 1/2] dmaengine: move module_/dma_device_put() after route free

[PATCH 1/2] dmaengine: move module_/dma_device_put() after route free

[Vinod Koul]

We call dma_device_put() and module_put() after invoking
.device_free_chan_resources callback, but we should also take care of
router devices and invoke this after .route_free callback. So move it
after .route_free

Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dmaengine.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index e316abe3672d..0505ea5b002f 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -427,15 +427,15 @@ static void dma_chan_put(struct dma_chan *chan)
 		chan->device->device_free_chan_resources(chan);
 	}
 
-	dma_device_put(chan->device);
-	module_put(dma_chan_to_owner(chan));
-
 	/* If the channel is used via a DMA request router, free the mapping */
 	if (chan->router && chan->router->route_free) {
 		chan->router->route_free(chan->router->dev, chan->route_data);
 		chan->router = NULL;
 		chan->route_data = NULL;
 	}
+
+	dma_device_put(chan->device);
+	module_put(dma_chan_to_owner(chan));
 }
 
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
-- 
2.23.0

[PATCH 2/2] dmaengine: print more meaningful error message

[Vinod Koul]

error log for dma_channel_table_init() failure pointed a mere
"initialization failure", which is not very helpful message, so print
additional details like function name and error code.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dmaengine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 0505ea5b002f..4ac77456e830 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -206,7 +206,7 @@ static int __init dma_channel_table_init(void)
 	}
 
 	if (err) {
-		pr_err("initialization failure\n");
+		pr_err("dmaengine dma_channel_table_init failure: %d\n", err);
 		for_each_dma_cap_mask(cap, dma_cap_mask_all)
 			free_percpu(channel_table[cap]);
 	}
-- 
2.23.0

Re: [PATCH 1/2] dmaengine: move module_/dma_device_put() after route free

[Logan Gunthorpe]

On 2019-12-23 10:03 p.m., Vinod Koul wrote:
> We call dma_device_put() and module_put() after invoking
> .device_free_chan_resources callback, but we should also take care of
> router devices and invoke this after .route_free callback. So move it
> after .route_free
> 
> Signed-off-by: Vinod Koul <vkoul@kernel.org>

Makes sense.

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

> ---
>  drivers/dma/dmaengine.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index e316abe3672d..0505ea5b002f 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -427,15 +427,15 @@ static void dma_chan_put(struct dma_chan *chan)
>  		chan->device->device_free_chan_resources(chan);
>  	}
>  
> -	dma_device_put(chan->device);
> -	module_put(dma_chan_to_owner(chan));
> -
>  	/* If the channel is used via a DMA request router, free the mapping */
>  	if (chan->router && chan->router->route_free) {
>  		chan->router->route_free(chan->router->dev, chan->route_data);
>  		chan->router = NULL;
>  		chan->route_data = NULL;
>  	}
> +
> +	dma_device_put(chan->device);
> +	module_put(dma_chan_to_owner(chan));
>  }
>  
>  enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
>