[PATCH 1/4] mci: core: bus-width property should override driver default

Sascha Hauer s.hauer at pengutronix.de
Wed Nov 18 23:52:43 PST 2015


On Wed, Nov 18, 2015 at 09:06:46PM +0000, Trent Piepho wrote:
> The OF code for parsing bus-width would only add the specified width
> to those the driver might have already set capability flags for.
> 
> Because of this, if the driver had set 8 or 4 bit width, it wasn't
> possible for the DT to specify that fewer pins were used on the board
> and a smaller width was necessary.
> 
> Change this so the width in the DT overrides whatever widths the
> driver says it supports.  There is no reason to have an incorrect
> device tree and it makes far more sense for the DT to override the
> driver default than for the driver default to override the DT.
> 
> The widths the driver puts in host_caps before calling mci_of_parse()
> are considered the default if the DT doesn't specify bus-width.  This
> should cause the least amount of change to existing boards, as despite
> a comment that no bus-width meant to use 1 bit, using the driver
> default is what was really happening.
> 
> Unfortunately, half of existing drivers default to the largest width
> they support while the other half default to the smallest.  Boards
> should just stick the width in the device tree.
> 
> Signed-off-by: Trent Piepho <tpiepho at kymetacorp.com>
> ---
>  drivers/mci/mci-core.c | 38 ++++++++++++++++++++++----------------
>  include/mci.h          |  2 ++
>  2 files changed, 24 insertions(+), 16 deletions(-)

Applied, thanks

Sascha



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