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 <[email protected]> >> Signed-off-by: Robert Baldyga <[email protected]> >> --- >> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
