[PATCH] of: give priority to the compatible match in __of_match_node()
Paul Gortmaker
paul.gortmaker at windriver.com
Thu Feb 20 05:25:54 EST 2014
On Thu, Feb 13, 2014 at 2:01 PM, Rob Herring <robherring2 at gmail.com> wrote:
> On Wed, Feb 12, 2014 at 5:38 AM, Kevin Hao <haokexin at gmail.com> wrote:
>> When the device node do have a compatible property, we definitely
>> prefer the compatible match besides the type and name. Only if
>> there is no such a match, we then consider the candidate which
>> doesn't have compatible entry but do match the type or name with
>> the device node.
>>
>> This is based on a patch from Sebastian Hesselbarth.
>> http://patchwork.ozlabs.org/patch/319434/
>>
>> I did some code refactoring and also fixed a bug in the original patch.
>
> I'm inclined to just revert this once again and avoid possibly
> breaking yet another platform.
Well, for what it is worth, today's (Feb19th) linux-next tree fails to boot
on my sbc8548. It fails with:
-----------------------------------------------
libphy: Freescale PowerQUICC MII Bus: probed
mdio_bus ethernet at e002400: /soc8548 at e0000000/ethernet at 24000/mdio at 520
PHY address 1312 is too large
libphy: Freescale PowerQUICC MII Bus: probed
libphy: Freescale PowerQUICC MII Bus: probed
mdio_bus ethernet at e002500: /soc8548 at e0000000/ethernet at 25000/mdio at 520
PHY address 1312 is too large
libphy: Freescale PowerQUICC MII Bus: probed
TCP: cubic registered
Initializing XFRM netlink socket
NET: Registered protocol family 17
<fail nfs mount>
-----------------------------------------------
On a normal boot, we should see this:
-----------------------------------------------
libphy: Freescale PowerQUICC MII Bus: probed
libphy: Freescale PowerQUICC MII Bus: probed
fsl-gianfar e0024000.ethernet: enabled errata workarounds, flags: 0x4
fsl-gianfar e0024000.ethernet eth0: mac: 02:e0:0c:00:05:fd
fsl-gianfar e0024000.ethernet eth0: Running with NAPI enabled
fsl-gianfar e0024000.ethernet eth0: RX BD ring size for Q[0]: 256
fsl-gianfar e0024000.ethernet eth0: TX BD ring size for Q[0]: 256
fsl-gianfar e0025000.ethernet: enabled errata workarounds, flags: 0x4
fsl-gianfar e0025000.ethernet eth1: mac: 02:e0:0c:00:06:fd
fsl-gianfar e0025000.ethernet eth1: Running with NAPI enabled
fsl-gianfar e0025000.ethernet eth1: RX BD ring size for Q[0]: 256
fsl-gianfar e0025000.ethernet eth1: TX BD ring size for Q[0]: 256
TCP: cubic registered
Initializing XFRM netlink socket
NET: Registered protocol family 17
-----------------------------------------------
Git bisect says:
ee8b26ad943aa34acc03ae6cde2b81d8d3d483d4 is the first bad commit
commit ee8b26ad943aa34acc03ae6cde2b81d8d3d483d4
Author: Kevin Hao <haokexin at gmail.com>
Date: Tue Feb 18 15:57:30 2014 +0800
of: reimplement the matching method for __of_match_node()
In the current implementation of __of_match_node(), it will compare
each given match entry against all the 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, we define a following priority order for the match, and
then scan all the entries to find the best match.
1. specific compatible && type && name
2. specific compatible && type
3. specific compatible && name
4. specific compatible
5. general compatible && type && name
6. general compatible && type
7. general compatible && name
8. general compatible
9. type && name
10. type
11. name
This is based on some pseudo-codes provided by Grant Likely.
Signed-off-by: Kevin Hao <haokexin at gmail.com>
[grant.likely: Changed multiplier to 4 which makes more sense]
Signed-off-by: Grant Likely <grant.likely at linaro.org>
:040000 040000 8f5dd19174417aece63b308ff299a5dbe2efa5a0
8401b0e3903e23e973845ee75b26b04345d803d2 M drivers
As a double check, I checked out the head of linux-next, and did a
revert of the above commit, and my sbc8548 can then boot properly.
Not doing anything fancy ; using the defconfig exactly as-is, and
ensuring the dtb is fresh from linux-next HEAD of today.
Thanks,
Paul.
--
>
> However, I think I would like to see this structured differently. We
> basically have 2 ways of matching: the existing pre-3.14 way and the
> desired match on best compatible only. All new bindings should match
> with the new way and the old way needs to be kept for compatibility.
> So lets structure the code that way. Search the match table first for
> best compatible with name and type NULL, then search the table the old
> way. I realize it appears you are doing this, but it is not clear this
> is the intent of the code. I would like to see this written as a patch
> with commit 105353145eafb3ea919 reverted first and you add a new match
> function to call first and then fallback to the existing function.
>
> Rob
>
>>
>> Cc: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
>> Signed-off-by: Kevin Hao <haokexin at gmail.com>
>> ---
>> drivers/of/base.c | 55 +++++++++++++++++++++++++++++++++++++------------------
>> 1 file changed, 37 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index ff85450d5683..9d655df458bd 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -730,32 +730,45 @@ out:
>> }
>> EXPORT_SYMBOL(of_find_node_with_property);
>>
>> +static int of_match_type_or_name(const struct device_node *node,
>> + const struct of_device_id *m)
>> +{
>> + 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);
>> +
>> + return match;
>> +}
>> +
>> 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;
>> + const struct of_device_id *m;
>> + int match;
>>
>> if (!matches)
>> return NULL;
>>
>> cp = __of_get_property(node, "compatible", &cplen);
>> - do {
>> - const struct of_device_id *m = matches;
>> + while (cp && (cplen > 0)) {
>> + m = matches;
>>
>> /* Check against matches with current compatible string */
>> 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 &= cp
>> - && !of_compat_cmp(m->compatible, cp,
>> + if (!m->compatible[0]) {
>> + m++;
>> + continue;
>> + }
>> +
>> + match = of_match_type_or_name(node, m);
>> + match &= cp && !of_compat_cmp(m->compatible, cp,
>> strlen(m->compatible));
>> if (match)
>> return m;
>> @@ -763,12 +776,18 @@ const struct of_device_id *__of_match_node(const struct of_device_id *matches,
>> }
>>
>> /* Get node's next compatible string */
>> - if (cp) {
>> - l = strlen(cp) + 1;
>> - cp += l;
>> - cplen -= l;
>> - }
>> - } while (cp && (cplen > 0));
>> + l = strlen(cp) + 1;
>> + cp += l;
>> + cplen -= l;
>> + }
>> +
>> + m = matches;
>> + /* Check against matches without compatible string */
>> + while (m->name[0] || m->type[0] || m->compatible[0]) {
>> + if (!m->compatible[0] && of_match_type_or_name(node, m))
>> + return m;
>> + m++;
>> + }
>>
>> return NULL;
>> }
>> --
>> 1.8.5.3
>>
>> --
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