serial: 8250_omap: pause DMA only if DMA transfer in progress
It is possible that DMA transfer is already complete but, completion handler is yet to be called, when dmaengine_pause() is called in case of error condition(like break/rx timeout). This leads to dmaengine_pause() API to return EINVAL (as descriptor is already NULL) causing rx_dma_broken flag to be set and effectively disabling RX DMA. Fix this by calling dmaengine_pause() only when transfer is in progress. Signed-off-by: Vignesh R <vigneshr@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ -790,6 +790,7 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
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{
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struct omap8250_priv *priv = p->port.private_data;
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struct uart_8250_dma *dma = p->dma;
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struct dma_tx_state state;
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unsigned long flags;
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int ret;
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@ -800,10 +801,12 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
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return;
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}
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ret = dmaengine_pause(dma->rxchan);
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if (WARN_ON_ONCE(ret))
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priv->rx_dma_broken = true;
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ret = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
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if (ret == DMA_IN_PROGRESS) {
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ret = dmaengine_pause(dma->rxchan);
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if (WARN_ON_ONCE(ret))
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priv->rx_dma_broken = true;
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}
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spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
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__dma_rx_do_complete(p);
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