[U-Boot] [PATCH 1/4] mmc: Change board_mmc_getcd() signature.

Marek Vasut
2011-12-05T11:02:06Z

> On 05/12/2011 11:00, Thierry Reding wrote:
> > * Marek Vasut wrote:
> >>> The new API no longer uses the extra cd parameter that was used
> >>> to store the card presence state. Instead, this information is
> >>> returned via the function's return value. board_mmc_getcd()
> >>> returns -1 to indicate that no card-detection mechanism is
> >>> implemented; 0 indicates that no card is present and 1 is
> >>> returned if it was detected that a card is present.
> >>>
> >>> Signed-off-by: Thierry Reding
> >>> <thierry.reding@avionic-design.de>
> >>
> >> A silly question -- why do we need this change ? Can you explain
> >> it in the changelog of V2 too?
> >
> > It's the first step in implementing card-detection. I discussed
> > this with Andy and he came up with the idea that board_mmc_getcd()
> > should really have had the mmc parameter as first argument in the
> > first place instead of the cd parameter.
>
> Ok, I get it now.
>
> > Furthermore, the cd parameter is used inconsistently in individual
> > implementations. After some discussion we came to the conclusion
> > that the cd parameter wasn't required at all and the same
> > information can be represented in the return value. The whole
> > discussion is in this thread:
> >
> > http://lists.denx.de/pipermail/u-boot/2011-November/110180.html
> >
> > It's not really a necessary change, but it makes board_mmc_getcd()
> > much more consistent with other MMC-related functions.
> >
> > Perhaps this last sentence would be a good explanation to put in
> > the v2 commit message?
>
> Ok, thanks - this explains much better which is your intention for the
> patchset. It is also not bad to add a reference to the above thread.
>
> Best regards,
> Stefano Babic

Yep, and when/if submitting V2, also make a cover letter (while also adding the
explanation to this patch's commit message).

Thanks!
M