2014-11-27 20:57 GMT+08:00 Arnd Bergmann [off-list ref]:

On Thursday 27 November 2014 19:59:46 Lyra Zhang wrote:

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2014-11-27 2:29 GMT+08:00 Murali Karicheri [off-list ref]:

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On 11/25/2014 07:16 AM, Chunyan Zhang wrote:

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Add a full sc9836-uart driver for SC9836 SoC which is based on the

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+#include<linux/clk.h>

How about sorting this includes? asm/irq.h go first followed linux/ in
alphabatical order?

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+static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
+{
+       struct uart_port *port = (struct uart_port *)dev_id;
+       u32 ims;
+
+       ims = serial_in(port, SPRD_IMSR);
+
+       serial_out(port, SPRD_ICLR, ~0);
+
+       if (ims&  (SPRD_IMSR_RX_FIFO_FULL |
+               SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT)) {
+               sprd_rx(irq, port);
+       }
+       if (ims&  SPRD_IMSR_TX_FIFO_EMPTY)
+               sprd_tx(irq, port);
+
+       return IRQ_HANDLED;

You are always returning IRQ_HANDLED and this is registered as a SHARED irq.
Is there a chance this handler is called and the irq event doesn't
belong to this device?

Murali

You are right, this is not a SHARED irq. I'll pass 0 for irqflags when
called 'devm_request_irq' in the next version patch.

I think you could also add

        if (!ims)
                return IRQ_NONE;

which would make it work on shared interrupt lines.

        Arnd

Yes, I saw this way in other serial drivers.
But, if then, there are two questions for me:
1. Why did some serial drivers need an UN_SHARED irq?
2. How can we choose a right way?

Thank you!

Best regards,
Chunyan