From 29d35f0b53d4bd82ebc37c500a8dd73da61318ff Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 6 Aug 2023 17:20:56 +0800 Subject: [PATCH] serial: 8250_dw: fall back to poll if there's no interrupt [ Upstream commit 22130dae0533c474e4e0db930a88caa9b397d083 ] When there's no irq(this can be due to various reasons, for example, no irq from HW support, or we just want to use poll solution, and so on), falling back to poll is still better than no support at all. Signed-off-by: Jisheng Zhang Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw") Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_dw.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 88035100b86c..a1f2259cc9a9 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -523,7 +523,10 @@ static int dw8250_probe(struct platform_device *pdev) if (!regs) return dev_err_probe(dev, -EINVAL, "no registers defined\n"); - irq = platform_get_irq(pdev, 0); + irq = platform_get_irq_optional(pdev, 0); + /* no interrupt -> fall back to polling */ + if (irq == -ENXIO) + irq = 0; if (irq < 0) return irq;