Thread (6 messages) 6 messages, 3 authors, 2023-08-21
STALE1068d LANDED
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 2/2] serial: 8250_dw: fall back to poll if there's no interrupt

From: Jisheng Zhang <jszhang@kernel.org>
Date: 2023-08-06 09:32:54
Also in: linux-serial, lkml
Subsystem: 8250/16?50 (and clone uarts) serial driver, synopsys designware 8250 uart driver, the rest, tty layer and serial drivers · Maintainers: Greg Kroah-Hartman, Ilpo Järvinen, Linus Torvalds, Jiri Slaby

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 <jszhang@kernel.org>
---
 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 7db51781289e..f4cafca1a7da 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;
 
-- 
2.40.1
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