serial: imx: simplify some conditions related to dma (686351f3) · Commits · 戴 / test

Neither .dma_is_txing nor .dma_is_rxing can evaluate to true if .dma_is_enabled evaluates to false: The only function that sets .dma_is_txing to a non-zero value is imx_dma_tx() which is only called if .dma_is_enabled is true. Same for .dma_is_rxing and start_rx_dma(). And before .dma_is_enabled is set to 0 when imx_shutdown calls imx_disable_dma(), .dma_is_rxing and .dma_is_txing are reset to zero before, too. For this reason sport->dma_is_enabled && sport->dma_is_rxing has the same value as sport->dma_is_rxing which allows to simplify three if conditions. Signed-off-by:

Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -413,7 +413,7 @@ static void imx_stop_tx(struct uart_port *port)
		* We are maybe in the SMP context, so if the DMA TX thread is running
		* on other cpu, we have to wait for it to finish.
		*/
		if (sport->dma_is_enabled && sport->dma_is_txing)
		if (sport->dma_is_txing)
		return;

		temp = imx_uart_readl(sport, UCR1);
		@@ -442,7 +442,7 @@ static void imx_stop_rx(struct uart_port *port)
		struct imx_port sport = (struct imx_port )port;
		unsigned long temp;

		if (sport->dma_is_enabled && sport->dma_is_rxing) {
		if (sport->dma_is_rxing) {
		if (sport->port.suspended) {
		dmaengine_terminate_all(sport->dma_chan_rx);
		sport->dma_is_rxing = 0;
		@@ -900,7 +900,7 @@ static unsigned int imx_tx_empty(struct uart_port *port)
		ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;

		/* If the TX DMA is working, return 0. */
		if (sport->dma_is_enabled && sport->dma_is_txing)
		if (sport->dma_is_txing)
		ret = 0;

		return ret;

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