Re: [PATCH 06/11] spi-dw: Force error on out of range chip select.

From: Dirk Brandewie
Date: Thu Jun 23 2011 - 00:14:43 EST

On 06/22/2011 08:51 PM, Grant Likely wrote:
On Wed, Jun 22, 2011 at 8:00 PM,<dirk.brandewie@xxxxxxxxx> wrote:
From: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>

BUG_ON() if the selected chip select is out of range.

Signed-off-by: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>
drivers/spi/spi-dw.h | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 860bc34..3fa4c13 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -178,8 +178,7 @@ static inline void spi_dw_set_clk(struct spi_dw *dws, u16 div)

static inline void spi_dw_chip_sel(struct spi_dw *dws, u16 cs)
- if (cs> dws->num_cs)
- return;
+ BUG_ON(cs>= dws->master->num_chipselect);

BUG is rather an over-reaction. The transfer should be rejected if
the cs# is invalid, and a warning message is appropriate, but BUG() is
too extreme.

This is extreme I agree, the current driver will fail silently if an out of range chip select is requested.

We can drop this one for now and I will put a proper check in probe/init so we won't get here.


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