[PATCH v3 6/6] serial: imx: Fix imx_shutdown procedure
From: martyn.welch@collabora.co.uk (Martyn Welch)
Date: 2017-09-21 16:18:46
Also in:
linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Nandor Han <redacted> In some cases, it looks that interrupts can happen after the dma was disabled and port was not yet shutdown. This will result in interrupts handled by imx_rxint. This commits updates the shutdown function to ensure that underlying components are disabled in the right order. This disables RX and TX blocks, then it disabled interrupts. In case DMA is enabled, it disables DMA and free corresponding resources. It disables UART port and stop clocks. Signed-off-by: Nandor Han <redacted> Signed-off-by: Romain Perier <redacted> Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk> --- drivers/tty/serial/imx.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 256b128..393c1c0 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c@@ -1368,44 +1368,40 @@ static void imx_shutdown(struct uart_port *port) unsigned long temp; unsigned long flags; - if (sport->dma_is_enabled) { - sport->dma_is_rxing = 0; - sport->dma_is_txing = 0; - dmaengine_terminate_sync(sport->dma_chan_tx); - dmaengine_terminate_sync(sport->dma_chan_rx); - + if (!sport->port.suspended) { spin_lock_irqsave(&sport->port.lock, flags); imx_stop_tx(port); imx_stop_rx(port); - imx_disable_dma(sport); + + if (sport->dma_is_inited && sport->dma_is_enabled) + imx_disable_dma(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); imx_uart_dma_exit(sport); } - mctrl_gpio_disable_ms(sport->gpios); - spin_lock_irqsave(&sport->port.lock, flags); temp = readl(sport->port.membase + UCR2); - temp &= ~(UCR2_TXEN); + temp &= ~(UCR2_TXEN | UCR2_RXEN); writel(temp, sport->port.membase + UCR2); + temp = readl(sport->port.membase + UCR4); + temp &= ~UCR4_OREN; + writel(temp, sport->port.membase + UCR4); spin_unlock_irqrestore(&sport->port.lock, flags); - /* - * Stop our timer. - */ - del_timer_sync(&sport->timer); + mctrl_gpio_disable_ms(sport->gpios); - /* - * Disable all interrupts, port and break condition. - */ + /* Stop our timer. */ + del_timer_sync(&sport->timer); + /* Disable port. */ spin_lock_irqsave(&sport->port.lock, flags); temp = readl(sport->port.membase + UCR1); - temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN); - + temp &= ~UCR1_UARTEN; writel(temp, sport->port.membase + UCR1); spin_unlock_irqrestore(&sport->port.lock, flags); + /* Disable clocks. */ clk_disable_unprepare(sport->clk_per); clk_disable_unprepare(sport->clk_ipg); }
--
1.8.3.1