[PATCH 4/5] tty: serial: 8250 core: add runtime pm
From: Felipe Balbi <hidden>
Date: 2014-07-16 15:16:48
Also in:
linux-omap, linux-serial, lkml
Hi, On Wed, Jul 16, 2014 at 04:45:02PM +0200, Sebastian Andrzej Siewior wrote:
quoted hunk ↗ jump to hunk
@@ -1280,6 +1285,7 @@ static void serial8250_stop_tx(struct uart_port *port) struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(port->dev); __stop_tx(up); /*@@ -1289,6 +1295,8 @@ static void serial8250_stop_tx(struct uart_port *port) up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } static void serial8250_start_tx(struct uart_port *port)@@ -1296,8 +1304,9 @@ static void serial8250_start_tx(struct uart_port *port) struct uart_8250_port *up = container_of(port, struct uart_8250_port, port); + pm_runtime_get_sync(port->dev); if (up->dma && !serial8250_tx_dma(up)) { - return; + goto out; } else if (!(up->ier & UART_IER_THRI)) { up->ier |= UART_IER_THRI; serial_port_out(port, UART_IER, up->ier);@@ -1318,6 +1327,9 @@ static void serial8250_start_tx(struct uart_port *port) up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } +out: + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev);
I wonder if you should get_sync() on start_tx() and only put_autosuspend() at stop_tx(). I guess the outcome would be largely the same, no ? well, other than in probe and other functions which need to make sure clocks are on, but it seems unnecessary to enable/disable in every function. -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140716/1ce5636b/attachment.sig>