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From: Stepan Ionichev <sozdayvek@gmail.com>
To: sunny.luo@amlogic.com
Cc: xianwei.zhao@amlogic.com, broonie@kernel.org,
	linux-amlogic@lists.infradead.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Stepan Ionichev <sozdayvek@gmail.com>
Subject: [PATCH] spi: amlogic-spisg: drop misleading NULL check on exdesc
Date: Wed,  6 May 2026 23:35:12 +0500	[thread overview]
Message-ID: <20260506183513.482-1-sozdayvek@gmail.com> (raw)

aml_spisg_setup_transfer() takes a non-NULL exdesc pointer; the
function dereferences exdesc unconditionally later in the body to
populate the SPI scatter-gather descriptors (tx_ccsg / rx_ccsg).
The sole caller, aml_spisg_transfer_one_message(), always passes a
valid pointer derived from kcalloc().

The "if (exdesc)" guard around the memset() at the start of the
function is therefore dead and misleading -- it suggests callers
may pass NULL when in fact they may not. smatch flags the
inconsistency:

  drivers/spi/spi-amlogic-spisg.c:314 aml_spisg_setup_transfer()
    error: we previously assumed 'exdesc' could be null (see line 261)

Drop the check; the unconditional memset matches the unconditional
dereferences elsewhere in the function and removes the inconsistency
that smatch reports.

No functional change.

Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
---
 drivers/spi/spi-amlogic-spisg.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/spi/spi-amlogic-spisg.c b/drivers/spi/spi-amlogic-spisg.c
index 19c5eba41..b2a916496 100644
--- a/drivers/spi/spi-amlogic-spisg.c
+++ b/drivers/spi/spi-amlogic-spisg.c
@@ -258,8 +258,7 @@ static int aml_spisg_setup_transfer(struct spisg_device *spisg,
 	int ret;
 
 	memset(desc, 0, sizeof(*desc));
-	if (exdesc)
-		memset(exdesc, 0, sizeof(*exdesc));
+	memset(exdesc, 0, sizeof(*exdesc));
 	aml_spisg_set_speed(spisg, xfer->speed_hz);
 	xfer->effective_speed_hz = spisg->effective_speed_hz;
 
-- 
2.43.0


             reply	other threads:[~2026-05-06 18:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-06 18:35 Stepan Ionichev [this message]
2026-05-07  2:43 ` [PATCH] spi: amlogic-spisg: drop misleading NULL check on exdesc Xianwei Zhao
2026-05-07  8:25 ` Mark Brown

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