dmaengine: ptdma: Move variable condition check to the first place and remove redundancy

The variable is dereferenced without first checking if it's null, leading
to the following warning: 'Variable dereferenced before check: desc.'

     drivers/dma/amd/ptdma/ptdma-dmaengine.c: pt_cmd_callback_work()
     warn: variable dereferenced before check 'desc'

Therefore, move the condition check for the 'desc' variable to the first
place and remove the redundant extra condition check.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/bfa0a979-ce9f-422d-92c3-34921155d048@stanley.mountain/
Fixes: 656543989457 ("dmaengine: ptdma: Utilize the AE4DMA engine's multi-queue functionality")
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Link: https://lore.kernel.org/r/20250421114215.1687073-1-Basavaraj.Natikar@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/amd/ptdma/ptdma-dmaengine.c b/drivers/dma/amd/ptdma/ptdma-dmaengine.c
index 715ac3ae067b857830db85e170787e30f3ae6b1d..81339664036f33a17fde887c51facc10543b6f40 100644 (file)
--- a/drivers/dma/amd/ptdma/ptdma-dmaengine.c
+++ b/drivers/dma/amd/ptdma/ptdma-dmaengine.c
@@ -342,6 +342,9 @@ static void pt_cmd_callback_work(void *data, int err)
        struct pt_dma_chan *chan;
        unsigned long flags;
 
+       if (!desc)
+               return;
+
        dma_chan = desc->vd.tx.chan;
        chan = to_pt_chan(dma_chan);
 
@@ -355,16 +358,14 @@ static void pt_cmd_callback_work(void *data, int err)
                desc->status = DMA_ERROR;
 
        spin_lock_irqsave(&chan->vc.lock, flags);
-       if (desc) {
-               if (desc->status != DMA_COMPLETE) {
-                       if (desc->status != DMA_ERROR)
-                               desc->status = DMA_COMPLETE;
+       if (desc->status != DMA_COMPLETE) {
+               if (desc->status != DMA_ERROR)
+                       desc->status = DMA_COMPLETE;
 
-                       dma_cookie_complete(tx_desc);
-                       dma_descriptor_unmap(tx_desc);
-               } else {
-                       tx_desc = NULL;
-               }
+               dma_cookie_complete(tx_desc);
+               dma_descriptor_unmap(tx_desc);
+       } else {
+               tx_desc = NULL;
        }
        spin_unlock_irqrestore(&chan->vc.lock, flags);