[PATCH] spi: bcm63xx-hsspi: bcmbca-hsspi: fix _be16 type usage

[PATCH] spi: bcm63xx-hsspi: bcmbca-hsspi: fix _be16 type usage

[William Zhang]

sparse tool report warnings: drivers/spi/spi-bcm63xx-hsspi.c:197:31:
sparse: sparse: cast from restricted __be16.

The controller requires big endian 16 bit data. Define an intermediate
u16 value and use __be16 piointer dereferncing for the data to avoid
directly casting to u16 and sparse warning.

Fixes: 85a84a616999 ("spi: bcm63xx-hsspi: Endianness fix for ARM based SoC")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202302110438.sQwQnU54-lkp@intel.com/

Signed-off-by: William Zhang <william.zhang@broadcom.com>

---

 drivers/spi/spi-bcm63xx-hsspi.c | 10 ++++++----
 drivers/spi/spi-bcmbca-hsspi.c  |  6 ++++--
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
index 1e9e906d297c..68093c045e0b 100644
--- a/drivers/spi/spi-bcm63xx-hsspi.c
+++ b/drivers/spi/spi-bcm63xx-hsspi.c
@@ -350,7 +350,7 @@ static int bcm63xx_hsspi_do_prepend_txrx(struct spi_device *spi,
 {
 	struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	const u8 *tx = t->tx_buf;
 	u8 *rx = t->rx_buf;
 	u32 reg = 0;
@@ -401,7 +401,8 @@ static int bcm63xx_hsspi_do_prepend_txrx(struct spi_device *spi,
 		memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN + bs->prepend_cnt, tx,
 			    t->len);
 
-	__raw_writew((u16)cpu_to_be16(opcode | t->len), bs->fifo);
+	*(__be16 *)(&val) = cpu_to_be16(opcode | t->len);
+	__raw_writew(val, bs->fifo);
 	/* enable interrupt */
 	if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)
 		__raw_writel(HSSPI_PINGx_CMD_DONE(0), bs->regs + HSSPI_INT_MASK_REG);
@@ -468,7 +469,7 @@ static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t)
 {
 	struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	int pending = t->len;
 	int step_size = HSSPI_BUFFER_LEN;
 	const u8 *tx = t->tx_buf;
@@ -511,7 +512,8 @@ static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t)
 			tx += curr_step;
 		}
 
-		__raw_writew((u16)cpu_to_be16(opcode | curr_step), bs->fifo);
+		*(__be16 *)(&val) = cpu_to_be16(opcode | curr_step);
+		__raw_writew(val, bs->fifo);
 
 		/* enable interrupt */
 		if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)
diff --git a/drivers/spi/spi-bcmbca-hsspi.c b/drivers/spi/spi-bcmbca-hsspi.c
index d58033251c02..e255241319ab 100644
--- a/drivers/spi/spi-bcmbca-hsspi.c
+++ b/drivers/spi/spi-bcmbca-hsspi.c
@@ -252,7 +252,7 @@ static int bcmbca_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t,
 {
 	struct bcmbca_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	int pending = t->len;
 	int step_size = HSSPI_BUFFER_LEN;
 	const u8 *tx = t->tx_buf;
@@ -292,7 +292,9 @@ static int bcmbca_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t,
 			memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN, tx, curr_step);
 			tx += curr_step;
 		}
-		__raw_writew((u16)cpu_to_be16(opcode | curr_step), bs->fifo);
+
+		*(__be16 *)(&val) = cpu_to_be16(opcode | curr_step);
+		__raw_writew(val, bs->fifo);
 
 		/* enable interrupt */
 		if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)
-- 
2.37.3

Re: [PATCH] spi: bcm63xx-hsspi: bcmbca-hsspi: fix _be16 type usage

[Mark Brown]

On Fri, 10 Feb 2023 19:27:59 -0800, William Zhang wrote:
> sparse tool report warnings: drivers/spi/spi-bcm63xx-hsspi.c:197:31:
> sparse: sparse: cast from restricted __be16.
> 
> The controller requires big endian 16 bit data. Define an intermediate
> u16 value and use __be16 piointer dereferncing for the data to avoid
> directly casting to u16 and sparse warning.
> 
> [...]

Applied to

   broonie/spi.git for-next

Thanks!

[1/1] spi: bcm63xx-hsspi: bcmbca-hsspi: fix _be16 type usage
      commit: 2cca486cad4bf51da57cdad150697476a702ab69

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark