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serial: sh-sci: Do not resubmit DMA descriptors 

Resubmission of DMA descriptors is explicitly forbidden by the DMA
engine API.

Hence pass DMA_CTRL_ACK to dmaengine_prep_slave_sg(), and prepare a new
DMA descriptor instead of reusing the old one.
Remove sci_port.desc_rx[], as there's no longer a need to access the
active descriptor.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Geert Uytterhoeven 2015-08-21 20:02:48 +02:00 committed by Greg Kroah-Hartman
parent 658daa95b6
commit 47aceb927f
1 changed files with 18 additions and 12 deletions
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30
drivers/tty/serial/sh-sci.c
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@ -104,7 +104,6 @@ struct sci_port {
struct dma_chan *chan_rx;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct dma_async_tx_descriptor *desc_rx[2];
dma_cookie_t cookie_tx;
dma_cookie_t cookie_rx[2];
dma_cookie_t active_rx;
@ -1397,11 +1396,11 @@ static void sci_submit_rx(struct sci_port *s)
struct dma_async_tx_descriptor *desc;
desc = dmaengine_prep_slave_sg(chan,
sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
sg, 1, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
s->desc_rx[i] = desc;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[i] = dmaengine_submit(desc);
@ -1420,10 +1419,8 @@ static void sci_submit_rx(struct sci_port *s)
fail:
if (i)
dmaengine_terminate_all(chan);
for (i = 0; i < 2; i++) {
s->desc_rx[i] = NULL;
for (i = 0; i < 2; i++)
s->cookie_rx[i] = -EINVAL;
}
s->active_rx = -EINVAL;
dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");
sci_rx_dma_release(s, true);
@ -1447,7 +1444,6 @@ static void work_fn_rx(struct work_struct *work)
s->active_rx);
return;
}
desc = s->desc_rx[new];
status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
if (status != DMA_COMPLETE) {
@ -1474,17 +1470,27 @@ static void work_fn_rx(struct work_struct *work)
return;
}
desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[new], 1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[new] = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_rx[new])) {
dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
sci_rx_dma_release(s, true);
return;
}
if (dma_submit_error(s->cookie_rx[new]))
goto fail;
s->active_rx = s->cookie_rx[!new];
dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
__func__, s->cookie_rx[new], new, s->active_rx);
return;
fail:
dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
sci_rx_dma_release(s, true);
}
static void work_fn_tx(struct work_struct *work)