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From: George Hilliard <thirtythreeforty@gmail.com>
To: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org, Neil Brown <neil@brown.name>,
	George Hilliard <thirtythreeforty@gmail.com>
Subject: [PATCH 08/10] staging: mt7621-mmc: Check for nonzero number of scatterlist entries
Date: Tue, 19 Feb 2019 22:17:52 -0700	[thread overview]
Message-ID: <20190220051754.12195-9-thirtythreeforty@gmail.com> (raw)
In-Reply-To: <20190220051754.12195-1-thirtythreeforty@gmail.com>

The buffer descriptor setup loop is correct only if it is setting up at
least one bd struct.  Besides, there is an error somewhere if
dma_map_sg() returns 0.  So add a paranoid check for this condition.

Signed-off-by: George Hilliard <thirtythreeforty@gmail.com>
---
 drivers/staging/mt7621-mmc/sd.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index 942c0d63d710..736e1d23b391 100644
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -594,7 +594,12 @@ static void msdc_dma_setup(struct msdc_host *host, struct msdc_dma *dma,
 	struct bd *bd;
 	u32 j;
 
-	BUG_ON(sglen > MAX_BD_NUM); /* not support currently */
+	// Shouldn't happen; we configure the mmc host layer
+	// based on MAX_BD_NUM:
+	BUG_ON(sglen > MAX_BD_NUM);
+	// Correct setup below requires at least one bd
+	// (and dma_map_sg should not return 0):
+	BUG_ON(sglen == 0);
 
 	gpd = dma->gpd;
 	bd  = dma->bd;
-- 
2.20.1


  parent reply	other threads:[~2019-02-20  5:18 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-20  5:17 mt7621-mmc driver improvements George Hilliard
2019-02-20  5:17 ` [PATCH 01/10] staging: mt7621-mmc: fix unused variable compiler warning George Hilliard
2019-02-20  5:17 ` [PATCH 02/10] staging: mt7621-mmc: Remove obsolete comments George Hilliard
2019-02-20  5:17 ` [PATCH 03/10] staging: mt7621-mmc: Remove references to nonexistent mt7621_spi_ops George Hilliard
2019-02-20  5:17 ` [PATCH 04/10] staging: mt7621-mmc: Fix warning when reloading module with debug msgs enabled George Hilliard
2019-02-20  5:17 ` [PATCH 05/10] staging: mt7621-mmc: Use pinctrl subsystem to select SDXC pin mode George Hilliard
2019-02-20 11:27   ` Jonas Gorski
2019-02-20  5:17 ` [PATCH 06/10] staging: mt7621-mmc: Bill the caller for I/O time George Hilliard
2019-02-20  5:17 ` [PATCH 07/10] staging: mt7621-mmc: Initialize completions a single time during probe George Hilliard
2019-02-20  5:17 ` George Hilliard [this message]
2019-02-20  5:17 ` [PATCH 09/10] staging: mt7621-mmc: Remove redundant host->mmc->f_max write George Hilliard
2019-02-20  5:17 ` [PATCH 10/10] staging: mt7621-mmc: Immediately notify mmc layer of card change detection George Hilliard

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