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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ben Dooks <ben.dooks@sifive.com>,
        Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 193/244] dmaengine: dw-axi-dmac: do not print NULL LLI during error
Date:   Tue, 23 Aug 2022 10:25:52 +0200
Message-Id: <20220823080105.842297214@linuxfoundation.org>
In-Reply-To: <20220823080059.091088642@linuxfoundation.org>
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From: Ben Dooks <ben.dooks@sifive.com>

[ Upstream commit 86cb0defe0e275453bc39e856bb523eb425a6537 ]

During debugging we have seen an issue where axi_chan_dump_lli()
is passed a NULL LLI pointer which ends up causing an OOPS due
to trying to get fields from it. Simply print NULL LLI and exit
to avoid this.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Link: https://lore.kernel.org/r/20220708170153.269991-3-ben.dooks@sifive.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index 35993ab92154..8f765e2d7c72 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -944,6 +944,11 @@ static int dw_axi_dma_chan_slave_config(struct dma_chan *dchan,
 static void axi_chan_dump_lli(struct axi_dma_chan *chan,
 			      struct axi_dma_hw_desc *desc)
 {
+	if (!desc->lli) {
+		dev_err(dchan2dev(&chan->vc.chan), "NULL LLI\n");
+		return;
+	}
+
 	dev_err(dchan2dev(&chan->vc.chan),
 		"SAR: 0x%llx DAR: 0x%llx LLP: 0x%llx BTS 0x%x CTL: 0x%x:%08x",
 		le64_to_cpu(desc->lli->sar),
-- 
2.35.1