2021-06-30 11:25:55

by Bing Fan

Subject: [PATCH v4] arm pl011 serial: support multi-irq request

From: Bing Fan <[email protected]>

In order to make pl011 work better, multiple interrupts are
required, such as TXIM, RXIM, RTIM, error interrupt(FE/PE/BE/OE);
at the same time, pl011 to GIC does not merge the interrupt
lines(each serial-interrupt corresponding to different GIC hardware
interrupt), so need to enable and request multiple gic interrupt
numbers in the driver.

Signed-off-by: Bing Fan <[email protected]>
---
drivers/tty/serial/amba-pl011.c | 35 ++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 78682c12156a..e84f4b9dff87 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1701,11 +1701,40 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
}
}

+static void pl011_release_irq(struct uart_amba_port *uap, unsigned int max_cnt)
+{
+ struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);
+ int i;
+
+ for (i = 0; i < max_cnt; i++) {
+ if (amba_dev->irq[i])
+ free_irq(amba_dev->irq[i], uap);
+ }
+}
+
static int pl011_allocate_irq(struct uart_amba_port *uap)
{
+ int ret = 0;
+ int i;
+ unsigned int virq;
+ struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);
+
pl011_write(uap->im, uap, REG_IMSC);

- return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
+ for (i = 0; i < AMBA_NR_IRQS; i++) {
+ virq = amba_dev->irq[i];
+ if (virq == 0)
+ break;
+
+ ret = request_irq(virq, pl011_int, IRQF_SHARED, dev_name(&amba_dev->dev), uap);
+ if (ret) {
+ dev_err(uap->port.dev, "request %u interrupt failed\n", virq);
+ pl011_release_irq(uap, i - 1);
+ break;
+ }
+ }
+
+ return ret;
}

/*
@@ -1864,7 +1893,7 @@ static void pl011_shutdown(struct uart_port *port)

pl011_dma_shutdown(uap);

- free_irq(uap->port.irq, uap);
+ pl011_release_irq(uap, AMBA_NR_IRQS);

pl011_disable_uart(uap);

@@ -1894,7 +1923,7 @@ static void sbsa_uart_shutdown(struct uart_port *port)

pl011_disable_interrupts(uap);

- free_irq(uap->port.irq, uap);
+ pl011_release_irq(uap, AMBA_NR_IRQS);

if (uap->port.ops->flush_buffer)
uap->port.ops->flush_buffer(port);
--
2.17.1

2021-06-30 12:29:29

by Greg KH

Subject: Re: [PATCH v4] arm pl011 serial: support multi-irq request

On Wed, Jun 30, 2021 at 07:25:05PM +0800, Bing Fan wrote:
> From: Bing Fan <[email protected]>
>
> In order to make pl011 work better, multiple interrupts are
> required, such as TXIM, RXIM, RTIM, error interrupt(FE/PE/BE/OE);
> at the same time, pl011 to GIC does not merge the interrupt
> lines(each serial-interrupt corresponding to different GIC hardware
> interrupt), so need to enable and request multiple gic interrupt
> numbers in the driver.
>
> Signed-off-by: Bing Fan <[email protected]>
> ---
> drivers/tty/serial/amba-pl011.c | 35 ++++++++++++++++++++++++++++++---
> 1 file changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 78682c12156a..e84f4b9dff87 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -1701,11 +1701,40 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
> }
> }
>
> +static void pl011_release_irq(struct uart_amba_port *uap, unsigned int max_cnt)
> +{
> + struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);

Pass in the amba_dev instead here, you already have a pointer to it at
all places, right?

> + int i;
> +
> + for (i = 0; i < max_cnt; i++) {
> + if (amba_dev->irq[i])
> + free_irq(amba_dev->irq[i], uap);
> + }

You do not need { } here, didn't checkpatch warn about this?

> +}
> +
> static int pl011_allocate_irq(struct uart_amba_port *uap)
> {
> + int ret = 0;
> + int i;
> + unsigned int virq;
> + struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);
> +
> pl011_write(uap->im, uap, REG_IMSC);
>
> - return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
> + for (i = 0; i < AMBA_NR_IRQS; i++) {
> + virq = amba_dev->irq[i];
> + if (virq == 0)
> + break;
> +
> + ret = request_irq(virq, pl011_int, IRQF_SHARED, dev_name(&amba_dev->dev), uap);
> + if (ret) {
> + dev_err(uap->port.dev, "request %u interrupt failed\n", virq);
> + pl011_release_irq(uap, i - 1);
> + break;
> + }
> + }
> +
> + return ret;
> }
>
> /*
> @@ -1864,7 +1893,7 @@ static void pl011_shutdown(struct uart_port *port)
>
> pl011_dma_shutdown(uap);
>
> - free_irq(uap->port.irq, uap);
> + pl011_release_irq(uap, AMBA_NR_IRQS);

Ah, so your original patch was not correct either, how well have you
tested these changes?

thanks,

greg k-h