From e75e6b2a2ff3af9724f2e6e25790cbe1f4b4dad8 Mon Sep 17 00:00:00 2001
From: Colin Cross <ccross@android.com>
Date: Wed, 16 Mar 2011 16:56:23 -0700
Subject: [PATCH] serial: tegra_hsuart: Call complete callbacks when cancelling
reqs
Updates the tegra_hsuart driver to match the changes in the Tegra
dma engine.
Change-Id: Iaaf8770166156c1a6d889a6a11bae517626781ee
Signed-off-by: Colin Cross <ccross@android.com>
---
drivers/serial/tegra_hsuart.c | 78 ++++++++++++++++++++++-------------
1 file changed, 49 insertions(+), 29 deletions(-)
diff --git a/drivers/serial/tegra_hsuart.c b/drivers/serial/tegra_hsuart.c
index 2c70ac7a7893..a7c7220b854b 100644
--- a/drivers/serial/tegra_hsuart.c
+++ b/drivers/serial/tegra_hsuart.c
@@ -255,30 +255,19 @@ static int tegra_start_dma_rx(struct tegra_uart_port *t)
static void tegra_rx_dma_threshold_callback(struct tegra_dma_req *req)
{
struct tegra_uart_port *t = req->dev;
- struct uart_port *u = &t->uport;
unsigned long flags;
- spin_lock_irqsave(&u->lock, flags);
+ spin_lock_irqsave(&t->uport.lock, flags);
do_handle_rx_dma(t);
- spin_unlock_irqrestore(&u->lock, flags);
+ spin_unlock_irqrestore(&t->uport.lock, flags);
}
-/* It is expected that the callers take the UART lock when this API is called.
- *
- * There are 2 contexts when this function is called:
- *
- * 1. DMA ISR - DMA ISR triggers the threshold complete calback, which calls the
- * dequue API which in-turn calls this callback. UART lock is taken during
- * the call to the threshold callback.
- *
- * 2. UART ISR - UART calls the dequue API which in-turn will call this API.
- * In this case, UART ISR takes the UART lock.
- * */
-static void tegra_rx_dma_complete_callback(struct tegra_dma_req *req)
+/* must be called with uart lock held */
+static void tegra_rx_dma_complete_req(struct tegra_uart_port *t,
+ struct tegra_dma_req *req)
{
- struct tegra_uart_port *t = req->dev;
struct uart_port *u = &t->uport;
struct tty_struct *tty = u->state->port.tty;
@@ -299,9 +288,24 @@ static void tegra_rx_dma_complete_callback(struct tegra_dma_req *req)
if (req->status == -TEGRA_DMA_REQ_ERROR_ABORTED)
return;
- spin_unlock(&u->lock);
tty_flip_buffer_push(u->state->port.tty);
- spin_lock(&u->lock);
+}
+
+static void tegra_rx_dma_complete_callback(struct tegra_dma_req *req)
+{
+ struct tegra_uart_port *t = req->dev;
+ unsigned long flags;
+
+ /*
+ * should never get called, dma should be dequeued during threshold
+ * callback
+ */
+
+ dev_warn(t->uport.dev, "possible rx overflow\n");
+
+ spin_lock_irqsave(&t->uport.lock, flags);
+ tegra_rx_dma_complete_req(t, req);
+ spin_unlock_irqrestore(&t->uport.lock, flags);
}
/* Lock already taken */
@@ -310,7 +314,9 @@ static void do_handle_rx_dma(struct tegra_uart_port *t)
struct uart_port *u = &t->uport;
if (t->rts_active)
set_rts(t, false);
- tegra_dma_dequeue(t->rx_dma);
+ if (!tegra_dma_dequeue_req(t->rx_dma, &t->rx_dma_req))
+ tegra_rx_dma_complete_req(t, &t->rx_dma_req);
+
tty_flip_buffer_push(u->state->port.tty);
/* enqueue the request again */
tegra_start_dma_rx(t);
@@ -481,22 +487,31 @@ static void tegra_tx_dma_complete_work(struct work_struct *work)
spin_unlock_irqrestore(&t->uport.lock, flags);
}
-static void tegra_tx_dma_complete_callback(struct tegra_dma_req *req)
+/* must be called with uart lock held */
+static void tegra_tx_dma_complete_req(struct tegra_uart_port *t,
+ struct tegra_dma_req *req)
{
- struct tegra_uart_port *t = req->dev;
struct circ_buf *xmit = &t->uport.state->xmit;
int count = req->bytes_transferred;
- unsigned long flags;
- dev_vdbg(t->uport.dev, "%s: %d\n", __func__, count);
-
- spin_lock_irqsave(&t->uport.lock, flags);
xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&t->uport);
schedule_work(&t->tx_work);
+}
+
+static void tegra_tx_dma_complete_callback(struct tegra_dma_req *req)
+{
+ struct tegra_uart_port *t = req->dev;
+ unsigned long flags;
+
+ dev_vdbg(t->uport.dev, "%s: %d\n", __func__, req->bytes_transferred);
+
+ spin_lock_irqsave(&t->uport.lock, flags);
+
+ tegra_tx_dma_complete_req(t, req);
spin_unlock_irqrestore(&t->uport.lock, flags);
}
@@ -591,7 +606,9 @@ static void tegra_stop_rx(struct uart_port *u)
t->rx_in_progress = 0;
}
if (t->use_rx_dma && t->rx_dma) {
- tegra_dma_dequeue(t->rx_dma);
+ if (!tegra_dma_dequeue_req(t->rx_dma, &t->rx_dma_req))
+ tegra_rx_dma_complete_req(t, &t->rx_dma_req);
+
tty_flip_buffer_push(u->state->port.tty);
}
@@ -981,8 +998,10 @@ static void tegra_stop_tx(struct uart_port *u)
t = container_of(u, struct tegra_uart_port, uport);
- if (t->use_tx_dma)
- tegra_dma_dequeue_req(t->tx_dma, &t->tx_dma_req);
+ if (t->use_tx_dma) {
+ if (!tegra_dma_dequeue_req(t->tx_dma, &t->tx_dma_req))
+ tegra_tx_dma_complete_req(t, &t->tx_dma_req);
+ }
return;
}
@@ -1133,7 +1152,8 @@ static void tegra_flush_buffer(struct uart_port *u)
t = container_of(u, struct tegra_uart_port, uport);
if (t->use_tx_dma) {
- tegra_dma_dequeue_req(t->tx_dma, &t->tx_dma_req);
+ if (!tegra_dma_dequeue_req(t->tx_dma, &t->tx_dma_req))
+ tegra_tx_dma_complete_req(t, &t->tx_dma_req);
t->tx_dma_req.size = 0;
}
return;
--
2.34.1