[PATCH RFC 1/3] amba: bus: Warn on adding an AMBA device without valid periphid

[Zijun Hu <zijun_hu@icloud.com>]

From: Zijun Hu <quic_zijuhu@quicinc.com>

In order to handle rare case that an AMBA device is added without valid
periphid, it is costly for @amba_bustype's match() to try to read periphid
from hardware, so remind user to configure periphid via DT|ACPI as far as
possible by warning message.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
---
 drivers/amba/bus.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 34bc880ca20b..cc3c57f83798 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -560,6 +560,9 @@ int amba_device_add(struct amba_device *dev, struct resource *parent)
 
 	/* If primecell ID isn't hard-coded, figure it out */
 	if (!dev->periphid) {
+		dev_warn(&dev->dev,
+			 "Periphid of AMBA device '%s' is not configured, please fix it\n",
+			 dev_name(&dev->dev));
 		/*
 		 * AMBA device uevents require reading its pid and cid
 		 * registers.  To do this, the device must be on, clocked and

-- 
2.34.1