Commit 873c2ae4 authored by Robert Jarzmik's avatar Robert Jarzmik Committed by Tim Gardner

dmaengine: pxa_dma: fix cyclic transfers

BugLink: http://bugs.launchpad.net/bugs/1555640

commit f1692127 upstream.

While testing audio with pxa2xx-ac97, underrun were happening while the
user application was correctly feeding the music. Debug proved that the
cyclic transfer is not cyclic, ie. the last descriptor did not loop on
the first.

Another issue is that the descriptor length was always set to 8192,
because of an trivial operator issue.

This was tested on a pxa27x platform.

Fixes: a57e16cf ("dmaengine: pxa: add pxa dmaengine driver")
Reported-by: default avatarVasily Khoruzhick <anarsoul@gmail.com>
Tested-by: default avatarVasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
parent a85af2c3
...@@ -583,6 +583,8 @@ static void set_updater_desc(struct pxad_desc_sw *sw_desc, ...@@ -583,6 +583,8 @@ static void set_updater_desc(struct pxad_desc_sw *sw_desc,
(PXA_DCMD_LENGTH & sizeof(u32)); (PXA_DCMD_LENGTH & sizeof(u32));
if (flags & DMA_PREP_INTERRUPT) if (flags & DMA_PREP_INTERRUPT)
updater->dcmd |= PXA_DCMD_ENDIRQEN; updater->dcmd |= PXA_DCMD_ENDIRQEN;
if (sw_desc->cyclic)
sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
} }
static bool is_desc_completed(struct virt_dma_desc *vd) static bool is_desc_completed(struct virt_dma_desc *vd)
...@@ -673,6 +675,10 @@ static irqreturn_t pxad_chan_handler(int irq, void *dev_id) ...@@ -673,6 +675,10 @@ static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
dev_dbg(&chan->vc.chan.dev->device, dev_dbg(&chan->vc.chan.dev->device,
"%s(): checking txd %p[%x]: completed=%d\n", "%s(): checking txd %p[%x]: completed=%d\n",
__func__, vd, vd->tx.cookie, is_desc_completed(vd)); __func__, vd, vd->tx.cookie, is_desc_completed(vd));
if (to_pxad_sw_desc(vd)->cyclic) {
vchan_cyclic_callback(vd);
break;
}
if (is_desc_completed(vd)) { if (is_desc_completed(vd)) {
list_del(&vd->node); list_del(&vd->node);
vchan_cookie_complete(vd); vchan_cookie_complete(vd);
...@@ -1080,7 +1086,7 @@ pxad_prep_dma_cyclic(struct dma_chan *dchan, ...@@ -1080,7 +1086,7 @@ pxad_prep_dma_cyclic(struct dma_chan *dchan,
return NULL; return NULL;
pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr); pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH | period_len); dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
dev_dbg(&chan->vc.chan.dev->device, dev_dbg(&chan->vc.chan.dev->device,
"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n", "%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
__func__, (unsigned long)buf_addr, len, period_len, dir, flags); __func__, (unsigned long)buf_addr, len, period_len, dir, flags);
......
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