On 02/11/2015 01:23 AM, Vinod Koul wrote:
> On Wed, Dec 10, 2014 at 11:55:17AM +0100, Robert Baldyga wrote:
>> This patch adds possibility to read residue of DMA transfer. It's useful
>> when we want to know how many bytes have been transferred before we
>> terminate channel. It can take place, for example, on timeout interrupt.
>>
>> Signed-off-by: Lukasz Czerwinski <l.czerwinski@xxxxxxxxxxx>
>> Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
>> ---
>> drivers/dma/pl330.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 66 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
>> index bdf40b5..2f4d561 100644
>> --- a/drivers/dma/pl330.c
>> +++ b/drivers/dma/pl330.c
>> @@ -504,6 +504,9 @@ struct dma_pl330_desc {
>>
>> enum desc_status status;
>>
>> + int bytes_requested;
>> + bool last;
>> +
>> /* The channel which currently holds this desc */
>> struct dma_pl330_chan *pchan;
>>
>> @@ -2182,11 +2185,68 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
>> pm_runtime_put_autosuspend(pch->dmac->ddma.dev);
>> }
>>
>> +int pl330_get_current_xferred_count(struct dma_pl330_chan *pch,
>> + struct dma_pl330_desc *desc)
>> +{
>> + struct pl330_thread *thrd = pch->thread;
>> + struct pl330_dmac *pl330 = pch->dmac;
>> + void __iomem *regs = thrd->dmac->base;
>> + u32 val, addr;
>> +
>> + pm_runtime_get_sync(pl330->ddma.dev);
>> + val = addr = 0;
>> + if (desc->rqcfg.src_inc) {
>> + val = readl(regs + SA(thrd->id));
>> + addr = desc->px.src_addr;
>> + } else {
>> + val = readl(regs + DA(thrd->id));
>> + addr = desc->px.dst_addr;
>> + }
>> + pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
>> + pm_runtime_put_autosuspend(pl330->ddma.dev);
>> + return val - addr;
>> +}
>> +
>> static enum dma_status
>> pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
>> struct dma_tx_state *txstate)
>> {
>> - return dma_cookie_status(chan, cookie, txstate);
>> + enum dma_status ret;
>> + unsigned long flags;
>> + struct dma_pl330_desc *desc, *running = NULL;
>> + struct dma_pl330_chan *pch = to_pchan(chan);
>> + unsigned int transferred, residual = 0;
>> +
>> + spin_lock_irqsave(&pch->lock, flags);
> You want to check the dma_cookie_status here first and then based on status
> go into residue calcaultion, that too only when the txstate is NON null.
>
Ok, I will send v4.
Thanks,
Robert Baldyga
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