On 02-05-20, 15:00, Rafał Hibner wrote:

Hello Vinod,

On 02.05.2020 14:32, Vinod Koul wrote:

quoted

Would it not be better to use list_del_init() where we delete it rather
than do the init here?

It is not a problem of list element itself not being initialized.
The problem is that during fault conditions (zynqmp_dma_reset) all
elements are moved to free list. List head however is not reinitialized.

In normal flow elements are removed by list_del and resubmitted to
free list with zynqmp_dma_free_descriptor.

static void zynqmp_dma_chan_desc_cleanup(struct zynqmp_dma_chan *chan)
{
    ...
    list_for_each_entry_safe(desc, next, &chan->done_list, node) {
        ...
        list_del(&desc->node);
        ...
        zynqmp_dma_free_descriptor(chan, desc);
    }
}

The zynqmp_dma_free_descriptor does not delete elements from the
list by itself.
I am not he author of this driver so I fixed it by
doing non intrusive changes.

Anyways, I do not see how using list_del_init would fix the bug.

Looking at this, i think it would make sense to do list_splice_init()
before we send the list to be freed.

Radhey/Appana are cced, they should test this.

-- 
~Vinod

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