On Thu, Nov 28, 2013 at 07:36:25PM +0100, Sebastian Hesselbarth wrote: > Currently, of_match_node compares each given match against all node's > compatible strings with of_device_is_compatible. > > To achieve multiple compatible strings per node with ordering from > specific to generic, this requires given matches to be ordered from > specific to generic. For most of the drivers this is not true and also > an alphabetical ordering is more sane there. > > Therefore, this patch modifies of_match_node to match each of the node's > compatible strings against all given matches first, before checking the > next compatible string. This implies that node's compatibles are ordered > from specific to generic while given matches can be in any order. > > Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> > --- > Cc: Grant Likely <grant.likely@xxxxxxxxxx> > Cc: Rob Herring <rob.herring@xxxxxxxxxxx> > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > Cc: Russell King <linux@xxxxxxxxxxxxxxxx> > Cc: devicetree@xxxxxxxxxxxxxxx > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > --- > drivers/of/base.c | 47 ++++++++++++++++++++++++++++++++--------------- > 1 file changed, 32 insertions(+), 15 deletions(-) Hi Sebastian, I think you're one in a long line of people attempting to fix this. I tried myself over a year ago (commit 107a84e61cdd 'of: match by compatible property first') but it caused a subtle regression late in the release cycle and was reverted (commit bc51b0c22ceb 'Revert "of: match by compatible property first"). Only recently there was another attempt [0] but it's pretty much equivalent to what I did back then. That said, I think you might actually have nailed it with this patch. From what I remember all earlier attempt failed because they didn't match all compatible/name/type combinations properly. I'm adding a few people on Cc who were involved with the other patches, perhaps they can give your patch a spin and see if it fixes things for them. Thierry [0]: https://lkml.org/lkml/2013/10/3/585 > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 7d4c70f..183a9c7 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -713,23 +713,37 @@ static > const struct of_device_id *__of_match_node(const struct of_device_id *matches, > const struct device_node *node) > { > + const char *cp; > + int cplen, l; > + > if (!matches) > return NULL; > > - while (matches->name[0] || matches->type[0] || matches->compatible[0]) { > - int match = 1; > - if (matches->name[0]) > - match &= node->name > - && !strcmp(matches->name, node->name); > - if (matches->type[0]) > - match &= node->type > - && !strcmp(matches->type, node->type); > - if (matches->compatible[0]) > - match &= __of_device_is_compatible(node, > - matches->compatible); > - if (match) > - return matches; > - matches++; > + cp = __of_get_property(node, "compatible", &cplen); > + if (!cp) > + return NULL; > + > + while (cplen > 0) { > + const struct of_device_id *m = matches; > + > + while (m->name[0] || m->type[0] || m->compatible[0]) { > + int match = 1; > + if (m->name[0]) > + match &= node->name > + && !strcmp(m->name, node->name); > + if (m->type[0]) > + match &= node->type > + && !strcmp(m->type, node->type); > + if (m->compatible[0]) > + match &= !of_compat_cmp(cp, m->compatible, > + strlen(m->compatible)); > + if (match) > + return m; > + m++; > + } > + l = strlen(cp) + 1; > + cp += l; > + cplen -= l; > } > return NULL; > } > @@ -739,7 +753,10 @@ const struct of_device_id *__of_match_node(const struct of_device_id *matches, > * @matches: array of of device match structures to search in > * @node: the of device structure to match against > * > - * Low level utility function used by device matching. > + * Low level utility function used by device matching. Matching order > + * is to compare each of the node's compatibles with all given matches > + * first. This implies node's compatible is sorted from specific to > + * generic while matches can be in any order. > */ > const struct of_device_id *of_match_node(const struct of_device_id *matches, > const struct device_node *node) > -- > 1.7.10.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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