From: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
This patch calls work_fn_rx() directly so that the driver can avoid
executing of next sci_dma_rx_complete() before work_fn_rx() completes.
Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@xxxxxxxxx>
---
This patch is based on the tty-next branch of Greg Kroah-Hartman's tty
tree.
v2 [Yoshihiro Kaneko]
* Move work_fn_rx() up and remove a function prototype accorded
drivers/tty/serial/sh-sci.c | 225 ++++++++++++++++++++++----------------------
1 file changed, 113 insertions(+), 112 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index e7d6566..5b216ea 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1251,6 +1251,118 @@ static unsigned int sci_get_mctrl(struct uart_port *port)
}
#ifdef CONFIG_SERIAL_SH_SCI_DMA
+static void work_fn_rx(struct work_struct *work)
+{
+ struct sci_port *s = container_of(work, struct sci_port, work_rx);
+ struct uart_port *port = &s->port;
+ struct dma_async_tx_descriptor *desc;
+ int new;
+
+ if (s->active_rx == s->cookie_rx[0]) {
+ new = 0;
+ } else if (s->active_rx == s->cookie_rx[1]) {
+ new = 1;
+ } else {
+ dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
+ return;
+ }
+ desc = s->desc_rx[new];
+
+ if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
+ DMA_COMPLETE) {
+ /* Handle incomplete DMA receive */
+ struct dma_chan *chan = s->chan_rx;
+ struct shdma_desc *sh_desc = container_of(desc,
+ struct shdma_desc, async_tx);
+ unsigned long flags;
+ int count;
+
+ dmaengine_terminate_all(chan);
+ dev_dbg(port->dev, "Read %zu bytes with cookie %d\n",
+ sh_desc->partial, sh_desc->cookie);
+
+ spin_lock_irqsave(&port->lock, flags);
+ count = sci_dma_rx_push(s, sh_desc->partial);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (count)
+ tty_flip_buffer_push(&port->state->port);
+
+ sci_submit_rx(s);
+
+ return;
+ }
+
+ s->cookie_rx[new] = desc->tx_submit(desc);
+ if (s->cookie_rx[new] < 0) {
+ dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
+ sci_rx_dma_release(s, true);
+ return;
+ }
+
+ s->active_rx = s->cookie_rx[!new];
+
+ dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n",
+ __func__, s->cookie_rx[new], new, s->active_rx);
+}
+
+static void work_fn_tx(struct work_struct *work)
+{
+ struct sci_port *s = container_of(work, struct sci_port, work_tx);
+ struct dma_async_tx_descriptor *desc;
+ struct dma_chan *chan = s->chan_tx;
+ struct uart_port *port = &s->port;
+ struct circ_buf *xmit = &port->state->xmit;
+ struct scatterlist *sg = &s->sg_tx;
+
+ /*
+ * DMA is idle now.
+ * Port xmit buffer is already mapped, and it is one page... Just adjust
+ * offsets and lengths. Since it is a circular buffer, we have to
+ * transmit till the end, and then the rest. Take the port lock to get a
+ * consistent xmit buffer state.
+ */
+ spin_lock_irq(&port->lock);
+ sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
+ sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
+ sg->offset;
+ sg_dma_len(sg) = min_t(int, CIRC_CNT(xmit->head, xmit->tail,
+ UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head, xmit->tail,
+ UART_XMIT_SIZE));
+ spin_unlock_irq(&port->lock);
+
+ BUG_ON(!sg_dma_len(sg));
+
+ desc = dmaengine_prep_slave_sg(chan,
+ sg, s->sg_len_tx, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ /* switch to PIO */
+ sci_tx_dma_release(s, true);
+ return;
+ }
+
+ dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
+
+ spin_lock_irq(&port->lock);
+ s->desc_tx = desc;
+ desc->callback = sci_dma_tx_complete;
+ desc->callback_param = s;
+ spin_unlock_irq(&port->lock);
+ s->cookie_tx = desc->tx_submit(desc);
+ if (s->cookie_tx < 0) {
+ dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
+ /* switch to PIO */
+ sci_tx_dma_release(s, true);
+ return;
+ }
+
+ dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
+ __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
+
+ dma_async_issue_pending(chan);
+}
+
static void sci_dma_tx_complete(void *arg)
{
struct sci_port *s = arg;
@@ -1341,7 +1453,7 @@ static void sci_dma_rx_complete(void *arg)
if (count)
tty_flip_buffer_push(&port->state->port);
- schedule_work(&s->work_rx);
+ work_fn_rx(&s->work_rx);
}
static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
@@ -1412,117 +1524,6 @@ static void sci_submit_rx(struct sci_port *s)
dma_async_issue_pending(chan);
}
-
-static void work_fn_rx(struct work_struct *work)
-{
- struct sci_port *s = container_of(work, struct sci_port, work_rx);
- struct uart_port *port = &s->port;
- struct dma_async_tx_descriptor *desc;
- int new;
-
- if (s->active_rx == s->cookie_rx[0]) {
- new = 0;
- } else if (s->active_rx == s->cookie_rx[1]) {
- new = 1;
- } else {
- dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
- return;
- }
- desc = s->desc_rx[new];
-
- if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
- DMA_COMPLETE) {
- /* Handle incomplete DMA receive */
- struct dma_chan *chan = s->chan_rx;
- struct shdma_desc *sh_desc = container_of(desc,
- struct shdma_desc, async_tx);
- unsigned long flags;
- int count;
-
- dmaengine_terminate_all(chan);
- dev_dbg(port->dev, "Read %zu bytes with cookie %d\n",
- sh_desc->partial, sh_desc->cookie);
-
- spin_lock_irqsave(&port->lock, flags);
- count = sci_dma_rx_push(s, sh_desc->partial);
- spin_unlock_irqrestore(&port->lock, flags);
-
- if (count)
- tty_flip_buffer_push(&port->state->port);
-
- sci_submit_rx(s);
-
- return;
- }
-
- s->cookie_rx[new] = desc->tx_submit(desc);
- if (s->cookie_rx[new] < 0) {
- dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
- sci_rx_dma_release(s, true);
- return;
- }
-
- s->active_rx = s->cookie_rx[!new];
-
- dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n",
- __func__, s->cookie_rx[new], new, s->active_rx);
-}
-
-static void work_fn_tx(struct work_struct *work)
-{
- struct sci_port *s = container_of(work, struct sci_port, work_tx);
- struct dma_async_tx_descriptor *desc;
- struct dma_chan *chan = s->chan_tx;
- struct uart_port *port = &s->port;
- struct circ_buf *xmit = &port->state->xmit;
- struct scatterlist *sg = &s->sg_tx;
-
- /*
- * DMA is idle now.
- * Port xmit buffer is already mapped, and it is one page... Just adjust
- * offsets and lengths. Since it is a circular buffer, we have to
- * transmit till the end, and then the rest. Take the port lock to get a
- * consistent xmit buffer state.
- */
- spin_lock_irq(&port->lock);
- sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
- sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
- sg->offset;
- sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
- CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
- spin_unlock_irq(&port->lock);
-
- BUG_ON(!sg_dma_len(sg));
-
- desc = dmaengine_prep_slave_sg(chan,
- sg, s->sg_len_tx, DMA_MEM_TO_DEV,
- DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
- if (!desc) {
- /* switch to PIO */
- sci_tx_dma_release(s, true);
- return;
- }
-
- dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
-
- spin_lock_irq(&port->lock);
- s->desc_tx = desc;
- desc->callback = sci_dma_tx_complete;
- desc->callback_param = s;
- spin_unlock_irq(&port->lock);
- s->cookie_tx = desc->tx_submit(desc);
- if (s->cookie_tx < 0) {
- dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
- /* switch to PIO */
- sci_tx_dma_release(s, true);
- return;
- }
-
- dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
- __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
-
- dma_async_issue_pending(chan);
-}
#endif
static void sci_start_tx(struct uart_port *port)
--
1.9.1
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