Hi Vinod,
On Fri, Aug 21, 2015 at 2:09 PM, Vinod Koul <vinod.koul@xxxxxxxxx> wrote:
> On Thu, Aug 20, 2015 at 04:00:56PM +0530, Rameshwar Prasad Sahu wrote:
>> This patch fixes the an locking issue where client callback performs
> ^^^^^^^^^^^^
> ??
>
>> further submission.
> Do you men you are preventing that or fixing for this to be allowed?
Fixing lock to allow client to submit further request in there
callback routine if they would like.
>
>>
>> Signed-off-by: Rameshwar Prasad Sahu <rsahu@xxxxxxx>
>> ---
>> drivers/dma/xgene-dma.c | 33 ++++++++++++++++++++++-----------
>> 1 file changed, 22 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
>> index d1c8809..0b82bc0 100644
>> --- a/drivers/dma/xgene-dma.c
>> +++ b/drivers/dma/xgene-dma.c
>> @@ -763,12 +763,17 @@ static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
>> struct xgene_dma_ring *ring = &chan->rx_ring;
>> struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
>> struct xgene_dma_desc_hw *desc_hw;
>> + struct list_head ld_completed;
>> u8 status;
>>
>> + INIT_LIST_HEAD(&ld_completed);
>> +
>> + spin_lock_bh(&chan->lock);
>> +
>> /* Clean already completed and acked descriptors */
>> xgene_dma_clean_completed_descriptor(chan);
>>
>> - /* Run the callback for each descriptor, in order */
>> + /* Move all completed descriptors to ld completed queue, in order */
>> list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
>> /* Get subsequent hw descriptor from DMA rx ring */
>> desc_hw = &ring->desc_hw[ring->head];
>> @@ -811,15 +816,17 @@ static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
>> /* Mark this hw descriptor as processed */
>> desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
>>
>> - xgene_dma_run_tx_complete_actions(chan, desc_sw);
>> -
>> - xgene_dma_clean_running_descriptor(chan, desc_sw);
>> -
>> /*
>> * Decrement the pending transaction count
>> * as we have processed one
>> */
>> chan->pending--;
>> +
>> + /*
>> + * Delete this node from ld running queue and append it to
>> + * ld completed queue for further processing
>> + */
>> + list_move_tail(&desc_sw->node, &ld_completed);
>> }
>>
>> /*
>> @@ -828,6 +835,14 @@ static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
>> * ahead and free the descriptors below.
>> */
>> xgene_chan_xfer_ld_pending(chan);
>> +
>> + spin_unlock_bh(&chan->lock);
>> +
>> + /* Run the callback for each descriptor, in order */
>> + list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
>> + xgene_dma_run_tx_complete_actions(chan, desc_sw);
>> + xgene_dma_clean_running_descriptor(chan, desc_sw);
>> + }
>> }
>>
>> static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
>> @@ -876,11 +891,11 @@ static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
>> if (!chan->desc_pool)
>> return;
>>
>> - spin_lock_bh(&chan->lock);
>> -
>> /* Process all running descriptor */
>> xgene_dma_cleanup_descriptors(chan);
>>
>> + spin_lock_bh(&chan->lock);
>> +
>> /* Clean all link descriptor queues */
>> xgene_dma_free_desc_list(chan, &chan->ld_pending);
>> xgene_dma_free_desc_list(chan, &chan->ld_running);
>> @@ -1200,15 +1215,11 @@ static void xgene_dma_tasklet_cb(unsigned long data)
>> {
>> struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
>>
>> - spin_lock_bh(&chan->lock);
>> -
>> /* Run all cleanup for descriptors which have been completed */
>> xgene_dma_cleanup_descriptors(chan);
>>
>> /* Re-enable DMA channel IRQ */
>> enable_irq(chan->rx_irq);
>> -
>> - spin_unlock_bh(&chan->lock);
>> }
>>
>> static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
>> --
>> 1.8.2.1
>>
>
> --
> ~Vinod
--
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