lkml.org 
[lkml]   [2009]   [Aug]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: New MMC maintainer needed
    On Fri, 31 Jul 2009 11:54:07 +0100
    Matt Fleming <matt@console-pimps.org> wrote:

    > On Fri, Jul 31, 2009 at 12:26:23PM +0200, Pierre Ossman wrote:
    > >
    > > [PATCH 0/32] mmc and omap_hsmmc patches
    > > http://marc.info/?t=124722953900010&r=1&w=2
    > >
    > > I haven't looked through these at all. The ones affecting the core
    > > probably need some thorough reviews.
    > >
    > > I did notice the patch to say which cards a controller supports though,
    > > and I'm very sceptical about that one. The scanning process should work
    > > anyway, and the performance impact should be negligible as it is only
    > > on init. So that patch only adds complexity and confusion IMO.
    > >
    >
    > How much complexity does it really add? Surely it's better to give the
    > host controller driver writers the ability to not entertain supporting
    > some cards if they cannot be used? If they want to avoid the scanning
    > process for certain cards, why not let them?
    >

    Let's look at the pros and cons of this:

    Con:

    - The scanning code gets less clear as you increase the number of
    possible paths through it.

    - Different systems will have different init sequences, possibly
    provoking bugs in the cards.

    - Host driver writers now have more capability bits they have to
    consider. And these might be less than obvious since SD/MMC/SDIO are
    normally compatible so these bits seem useless.

    - With the current logic (which was better in the first version),
    "normal" drivers will have to explicitly state that they work as
    intended by setting all bits.

    Pro:

    - A slightly reduced scanning time.


    I simply don't see it as being worth it. Linux patches generally need
    to provide the answer to "Why?", not just be able to avoid "Why not?".

    Rgds
    --
    -- Pierre Ossman

    WARNING: This correspondence is being monitored by the
    Swedish government. Make sure your server uses encryption
    for SMTP traffic and consider using PGP for end-to-end
    encryption.
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2009-08-03 12:37    [W:0.043 / U:30.828 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site