On 2021-08-13 16:04, Greg KH wrote:

On Fri, Aug 13, 2021 at 03:08:48PM +0100, Robin Murphy wrote:

quoted

Hi Greg,

On 2021-08-13 09:17, Greg KH wrote:

quoted

On Fri, Aug 13, 2021 at 03:56:01PM +0800, Bing Fan wrote:

quoted

在 8/13/2021 15:19, Greg KH 写道:

quoted

On Fri, Aug 13, 2021 at 11:31:30AM +0800, Bing Fan wrote:

quoted

From: Bing Fan <redacted>

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 <redacted>
---
    drivers/tty/serial/amba-pl011.c | 39 +++++++++++++++++++++++++++++++--
    1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index e14f3378b8a0..eaac3431459c 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c

@@ -1701,6 +1701,41 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
    	}
    }
+static void pl011_release_multi_irqs(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_multi_irqs(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);
+
+	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_multi_irqs(uap, i - 1);
+			break;
+		}
+	}
+
+	return ret;
+}

This function looks identical to pl011_allocate_irq(), so what is the
difference here?  Why is this still needed at all?  What does it do that
is different from pl011_allocate_irq()?

The v6-patch is based on master of
git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git, not tty-next.

Always submit patches based on tty-next if you want them accepted into
that tree.

quoted

As below, the pl011_allocate_irq function supports single irq request only,
which different from pl011_allocate_multi_irqs.

static int pl011_allocate_irq(struct uart_amba_port *uap)
{
      pl011_write(uap->im, uap, REG_IMSC);

      return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011",
uap);
}

Ok, but that does not reflect what is in my tree to be merged for
5.15-rc1.  What is wrong with the code in there that is incorrect and
needs to be changed?

As reported by Qian Cai, it blows up on ACPI-based systems by assuming
port.dev is an amba_device when in fact in that situation it's a
platform_device. If you're able to drop the current patch from your tree
that would probably be the best thing to do for the moment.

I have not seen any such bug report.

It's the thread on the v5 patch that you've just replied to ;)

If something needs to be reverted in linux-next, (i.e. in my tty-next
branch), please let me know.  Ideally by sending a pathc to do so...

Since I'm only really involved here off the back of a drive-by review 
comment, I'll leave that up to Qian.

Cheers,
Robin.