From: Stanislaw Gruszka Date: Thu, 15 Jan 2009 21:50:44 +0000 (-0800) Subject: atmel_spi: allow transfer when max_speed_hz = 0 X-Git-Tag: v3.0~10898 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5b96f1729064453e09805a387378e0644da1c937;p=platform%2Fkernel%2Flinux-amlogic.git atmel_spi: allow transfer when max_speed_hz = 0 For some reason I have to slowdown clock to touchscreen device. In atmel_spi_setup() there is comment that max_speed_hz == 0 means as slow as possible and divider is set to maximum value. But in atmel_spi_transfer() function is check against not zero max_speed_hz with EINVAL returned. Probably driver should setup divider for each transfer based on transfer->speed_hz value, but I think that would be not necessary overhead as all used devices have constant clock. Below patch works fine for me. Signed-off-by: Stanislaw Gruszka Signed-off-by: Haavard Skinnemoen Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index 5e39bac..56ff3e6 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -670,8 +670,7 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) dev_dbg(controller, "new message %p submitted for %s\n", msg, spi->dev.bus_id); - if (unlikely(list_empty(&msg->transfers) - || !spi->max_speed_hz)) + if (unlikely(list_empty(&msg->transfers))) return -EINVAL; if (as->stopping)