Re: [PATCH next] of/fdt: Fix defined but not used compiler warning

From: Frank Rowand
Date: Wed Jun 12 2019 - 14:33:50 EST


On 6/12/19 10:00 AM, Rob Herring wrote:
> On Wed, Jun 12, 2019 at 10:45 AM Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>>
>> Hi Kefeng,
>>
>> If Rob agrees, I'd like to see one more change in this patch.
>>
>> Since the only caller of of_fdt_match() is of_flat_dt_match(),
>> can you move the body of of_fdt_match() into of_flat_dt_match()
>> and eliminate of_fdt_match()?
>
> That's fine as long as we think there's never any use for of_fdt_match
> after init? Fixup of nodes in an overlay for example.

We can always re-expose the functionality as of_fdt_match() in the future
if the need arises. But Stephen's recent patch was moving in the opposite
direction, removing of_fdt_match() from the header file and making it
static.

-Frank

>
> Rob
>
>>
>> (Noting that of_flat_dt_match() consists only of the call to
>> of_fdt_match().)
>>
>> -Frank
>>
>>
>> On 6/11/19 6:00 PM, Kefeng Wang wrote:
>>> When CONFIG_OF_EARLY_FLATTREE is disabled, there is a compiler warning,
>>>
>>> drivers/of/fdt.c:129:19: warning: âof_fdt_matchâ defined but not used [-Wunused-function]
>>> static int __init of_fdt_match(const void *blob, unsigned long node,
>>>
>>> Move of_fdt_match() and of_fdt_is_compatible() under CONFIG_OF_EARLY_FLATTREE
>>> to fix it.
>>>
>>> Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx>
>>> Cc: Rob Herring <robh@xxxxxxxxxx>
>>> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>>> ---
>>> drivers/of/fdt.c | 106 +++++++++++++++++++++++------------------------
>>> 1 file changed, 53 insertions(+), 53 deletions(-)
>>>
>>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
>>> index 3d36b5afd9bd..d6afd5b22940 100644
>>> --- a/drivers/of/fdt.c
>>> +++ b/drivers/of/fdt.c
>>> @@ -78,38 +78,6 @@ void __init of_fdt_limit_memory(int limit)
>>> }
>>> }
>>>
>>> -/**
>>> - * of_fdt_is_compatible - Return true if given node from the given blob has
>>> - * compat in its compatible list
>>> - * @blob: A device tree blob
>>> - * @node: node to test
>>> - * @compat: compatible string to compare with compatible list.
>>> - *
>>> - * On match, returns a non-zero value with smaller values returned for more
>>> - * specific compatible values.
>>> - */
>>> -static int of_fdt_is_compatible(const void *blob,
>>> - unsigned long node, const char *compat)
>>> -{
>>> - const char *cp;
>>> - int cplen;
>>> - unsigned long l, score = 0;
>>> -
>>> - cp = fdt_getprop(blob, node, "compatible", &cplen);
>>> - if (cp == NULL)
>>> - return 0;
>>> - while (cplen > 0) {
>>> - score++;
>>> - if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
>>> - return score;
>>> - l = strlen(cp) + 1;
>>> - cp += l;
>>> - cplen -= l;
>>> - }
>>> -
>>> - return 0;
>>> -}
>>> -
>>> static bool of_fdt_device_is_available(const void *blob, unsigned long node)
>>> {
>>> const char *status = fdt_getprop(blob, node, "status", NULL);
>>> @@ -123,27 +91,6 @@ static bool of_fdt_device_is_available(const void *blob, unsigned long node)
>>> return false;
>>> }
>>>
>>> -/**
>>> - * of_fdt_match - Return true if node matches a list of compatible values
>>> - */
>>> -static int __init of_fdt_match(const void *blob, unsigned long node,> - const char *const *compat)
>>> -{
>>> - unsigned int tmp, score = 0;
>>> -
>>> - if (!compat)
>>> - return 0;
>>> -
>>> - while (*compat) {
>>> - tmp = of_fdt_is_compatible(blob, node, *compat);
>>> - if (tmp && (score == 0 || (tmp < score)))
>>> - score = tmp;
>>> - compat++;
>>> - }
>>> -
>>> - return score;
>>> -}
>>> -
>>> static void *unflatten_dt_alloc(void **mem, unsigned long size,
>>> unsigned long align)
>>> {
>>> @@ -764,6 +711,59 @@ const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
>>> return fdt_getprop(initial_boot_params, node, name, size);
>>> }
>>>
>>> +/**
>>> + * of_fdt_is_compatible - Return true if given node from the given blob has
>>> + * compat in its compatible list
>>> + * @blob: A device tree blob
>>> + * @node: node to test
>>> + * @compat: compatible string to compare with compatible list.
>>> + *
>>> + * On match, returns a non-zero value with smaller values returned for more
>>> + * specific compatible values.
>>> + */
>>> +static int of_fdt_is_compatible(const void *blob,
>>> + unsigned long node, const char *compat)
>>> +{
>>> + const char *cp;
>>> + int cplen;
>>> + unsigned long l, score = 0;
>>> +
>>> + cp = fdt_getprop(blob, node, "compatible", &cplen);
>>> + if (cp == NULL)
>>> + return 0;
>>> + while (cplen > 0) {
>>> + score++;
>>> + if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
>>> + return score;
>>> + l = strlen(cp) + 1;
>>> + cp += l;
>>> + cplen -= l;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * of_fdt_match - Return true if node matches a list of compatible values
>>> + */
>>> +static int __init of_fdt_match(const void *blob, unsigned long node,
>>> + const char *const *compat)
>>> +{
>>> + unsigned int tmp, score = 0;
>>> +
>>> + if (!compat)
>>> + return 0;
>>> +
>>> + while (*compat) {
>>> + tmp = of_fdt_is_compatible(blob, node, *compat);
>>> + if (tmp && (score == 0 || (tmp < score)))
>>> + score = tmp;
>>> + compat++;
>>> + }
>>> +
>>> + return score;
>>> +}
>>> +
>>> /**
>>> * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
>>> * @node: node to test
>>>
>>
>