2009-11-24 08:29:37

by Mike Rapoport

Subject: [PATCH] backlight: tdo24m: ensure chip select changes between transfers

Some SPI host drivers do not change chip select betwen transfers unless
.cs_chnage field is explicitly set. The LCD spec requires chip select
change between consecuitive transfers, so ensure it at the SPI driver
level.

Signed-off-by: Mike Rapoport <[email protected]>
---
drivers/video/backlight/tdo24m.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/video/backlight/tdo24m.c b/drivers/video/backlight/tdo24m.c
index bbfb502..4a3d46e 100644
--- a/drivers/video/backlight/tdo24m.c
+++ b/drivers/video/backlight/tdo24m.c
@@ -367,6 +367,7 @@ static int __devinit tdo24m_probe(struct spi_device *spi)

spi_message_init(m);

+ x->cs_change = 1;
x->tx_buf = &lcd->buf[0];
spi_message_add_tail(x, m);

--
1.6.4.4

2009-11-29 03:04:24

by Eric Miao

Subject: Re: [PATCH] backlight: tdo24m: ensure chip select changes between transfers

On Tue, Nov 24, 2009 at 4:25 PM, Mike Rapoport <[email protected]> wrote:
> Some SPI host drivers do not change chip select betwen transfers unless
> .cs_chnage field is explicitly set. The LCD spec requires chip select
> change between consecuitive transfers, so ensure it at the SPI driver
> level.
>
> Signed-off-by: Mike Rapoport <[email protected]>

Applied to 'devel'.

Richard,

I'd still hope this can be merged via your backlight tree, and let me know
when that's done so that I can drop this here.