linux-kernel - [PATCH v2] bus: omap_l3_smx: identify timeout source before rebooting

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Message-Id: <20230731210347.1048060-1-absicsz@gmail.com>
Date:   Mon, 31 Jul 2023 23:03:47 +0200
From:   "Sicelo A. Mhlongo" <absicsz@...il.com>
To:     linux-omap@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, Tony Lindgren <tony@...mide.com>,
        "Sicelo A. Mhlongo" <absicsz@...il.com>
Subject: [PATCH v2] bus: omap_l3_smx: identify timeout source before rebooting

Identify and print the error source before rebooting the board due to an l3
application timeout error, by delaying the BUG_ON. This is helpful when
debugging, e.g. via serial.

Signed-off-by: Sicelo A. Mhlongo <absicsz@...il.com>
---
 drivers/bus/omap_l3_smx.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/omap_l3_smx.c b/drivers/bus/omap_l3_smx.c
index bb1606f5ce2d..0ccde12e33c0 100644
--- a/drivers/bus/omap_l3_smx.c
+++ b/drivers/bus/omap_l3_smx.c
@@ -170,11 +170,9 @@ static irqreturn_t omap3_l3_app_irq(int irq, void *_l3)
 		status = omap3_l3_readll(l3->rt, L3_SI_FLAG_STATUS_0);
 		/*
 		 * if we have a timeout error, there's nothing we can
-		 * do besides rebooting the board. So let's BUG on any
-		 * of such errors and handle the others. timeout error
-		 * is severe and not expected to occur.
+		 * do besides rebooting the board after identifying the
+		 * error source.
 		 */
-		BUG_ON(status & L3_STATUS_0_TIMEOUT_MASK);
 	} else {
 		status = omap3_l3_readll(l3->rt, L3_SI_FLAG_STATUS_1);
 		/* No timeout error for debug sources */
@@ -190,6 +188,12 @@ static irqreturn_t omap3_l3_app_irq(int irq, void *_l3)
 		ret |= omap3_l3_block_irq(l3, error, error_addr);
 	}
 
+	/*
+	 * BUG on application timeout errors since they are severe and not
+	 * expected to occur.
+	 */
+	BUG_ON(!int_type && status & L3_STATUS_0_TIMEOUT_MASK);
+
 	/* Clear the status register */
 	clear = (L3_AGENT_STATUS_CLEAR_IA << int_type) |
 		L3_AGENT_STATUS_CLEAR_TA;
-- 
2.40.1