When unbinding the console uart, we want to power down the uart hardware
on remove. For the console uart, the normal shutdown path will never get
called as the cons_filp stays open. Let's rearrange the dma related
functions a bit so we can call driver shutdown also on console uart rebind.
Currently we set up->dma on probe, but that causes issues calling
omap_8250_shutdown() on remove. The dma startup will not get called on
the next rebind as we still have up->dma set from probe.
Note that serial8250_release_dma() already checks for dma so we can
remove the check for it in 8205_omap driver.
With these changes we also avoid hogging dma virtual channels for the
unused uarts that may be limited on some devices.
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_omap.c | 36 ++++++++++++++++-------------
1 file changed, 20 insertions(+), 16 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -679,6 +679,7 @@ static int omap_8250_startup(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
struct omap8250_priv *priv = port->private_data;
+ struct uart_8250_dma *dma = &priv->omap8250_dma;
int ret;
if (priv->wakeirq) {
@@ -697,16 +698,16 @@ static int omap_8250_startup(struct uart_port *port)
up->msr_saved_flags = 0;
/* Disable DMA for console UART */
- if (uart_console(port))
- up->dma = NULL;
-
- if (up->dma) {
+ if (dma->fn && !uart_console(port)) {
+ up->dma = &priv->omap8250_dma;
ret = serial8250_request_dma(up);
if (ret) {
dev_warn_ratelimited(port->dev,
"failed to request DMA\n");
up->dma = NULL;
}
+ } else {
+ up->dma = NULL;
}
up->ier = UART_IER_RLSI | UART_IER_RDI;
@@ -752,8 +753,8 @@ static void omap_8250_shutdown(struct uart_port *port)
disable_irq_nosync(up->port.irq);
dev_pm_clear_wake_irq(port->dev);
- if (up->dma)
- serial8250_release_dma(up);
+ serial8250_release_dma(up);
+ up->dma = NULL;
/*
* Disable break condition and FIFOs
@@ -1499,24 +1500,24 @@ static int omap8250_probe(struct platform_device *pdev)
ret = of_property_count_strings(np, "dma-names");
if (ret == 2) {
struct omap8250_dma_params *dma_params = NULL;
+ struct uart_8250_dma *dma = &priv->omap8250_dma;
- up.dma = &priv->omap8250_dma;
- up.dma->fn = the_no_dma_filter_fn;
- up.dma->tx_dma = omap_8250_tx_dma;
- up.dma->rx_dma = omap_8250_rx_dma;
+ dma->fn = the_no_dma_filter_fn;
+ dma->tx_dma = omap_8250_tx_dma;
+ dma->rx_dma = omap_8250_rx_dma;
if (pdata)
dma_params = pdata->dma_params;
if (dma_params) {
- up.dma->rx_size = dma_params->rx_size;
- up.dma->rxconf.src_maxburst = dma_params->rx_trigger;
- up.dma->txconf.dst_maxburst = dma_params->tx_trigger;
+ dma->rx_size = dma_params->rx_size;
+ dma->rxconf.src_maxburst = dma_params->rx_trigger;
+ dma->txconf.dst_maxburst = dma_params->tx_trigger;
priv->rx_trigger = dma_params->rx_trigger;
priv->tx_trigger = dma_params->tx_trigger;
} else {
- up.dma->rx_size = RX_TRIGGER;
- up.dma->rxconf.src_maxburst = RX_TRIGGER;
- up.dma->txconf.dst_maxburst = TX_TRIGGER;
+ dma->rx_size = RX_TRIGGER;
+ dma->rxconf.src_maxburst = RX_TRIGGER;
+ dma->txconf.dst_maxburst = TX_TRIGGER;
}
}
#endif
@@ -1550,12 +1551,15 @@ static int omap8250_probe(struct platform_device *pdev)
static int omap8250_remove(struct platform_device *pdev)
{
struct omap8250_priv *priv = platform_get_drvdata(pdev);
+ struct uart_8250_port *up;
int err;
err = pm_runtime_resume_and_get(&pdev->dev);
if (err)
return err;
+ up = serial8250_get_port(priv->line);
+ omap_8250_shutdown(&up->port);
serial8250_unregister_port(priv->line);
priv->line = -ENODEV;
pm_runtime_dont_use_autosuspend(&pdev->dev);
--
2.40.1
