On 04/17/2013 11:27 PM, Jon Hunter wrote:
>
> On 04/17/2013 03:34 PM, Javier Martinez Canillas wrote:
>> The GPMC DT probe function use for_each_node_by_name() to search
>> child device nodes of the GPMC controller. But this function does
>> not use the GPMC device node as the root of the search and instead
>> search across the complete Device Tree.
>>
>> This means that any device node on the DT that is using any of the
>> GPMC child nodes names searched for will be returned even if they
>> are not connected to the GPMC, making the gpmc_probe_xxx_child()
>> function to fail.
>>
>> Fix this by using the GPMC device node as the search root so the
>> search will be restricted to its children.
>>
>> Reported-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
>> Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
>> ---
>>
>> Changes since v1 (suggested by Jon Hunter):
>> - Split the search for GPMC child nodes and only warn if a
>> child probe fails on two different patches
>> - Don't probe all childs unnecesary if a previous matched
>>
>> arch/arm/mach-omap2/gpmc.c | 33 ++++++++++-----------------------
>> 1 files changed, 10 insertions(+), 23 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
>> index ed946df..6166847 100644
>> --- a/arch/arm/mach-omap2/gpmc.c
>> +++ b/arch/arm/mach-omap2/gpmc.c
>> @@ -1520,32 +1520,19 @@ static int gpmc_probe_dt(struct platform_device *pdev)
>> return ret;
>> }
>>
>> - for_each_node_by_name(child, "nand") {
>> - ret = gpmc_probe_nand_child(pdev, child);
>> - if (ret < 0) {
>> - of_node_put(child);
>> - return ret;
>> - }
>> - }
>> + for_each_child_of_node(pdev->dev.of_node, child) {
>>
>> - for_each_node_by_name(child, "onenand") {
>> - ret = gpmc_probe_onenand_child(pdev, child);
>> - if (ret < 0) {
>> - of_node_put(child);
>> - return ret;
>> - }
>> - }
>> + if (!child->name)
>> + continue;
>>
>> - for_each_node_by_name(child, "nor") {
>> - ret = gpmc_probe_generic_child(pdev, child);
>> - if (ret < 0) {
>> - of_node_put(child);
>> - return ret;
>> - }
>> - }
>> + if (of_node_cmp(child->name, "nand") == 0)
>> + ret = gpmc_probe_nand_child(pdev, child);
>> + else if (of_node_cmp(child->name, "onenand") == 0)
>> + ret = gpmc_probe_onenand_child(pdev, child);
>> + else if (of_node_cmp(child->name, "ethernet") == 0 ||
>> + of_node_cmp(child->name, "nor") == 0)
>> + ret = gpmc_probe_generic_child(pdev, child);
>>
>> - for_each_node_by_name(child, "ethernet") {
>> - ret = gpmc_probe_generic_child(pdev, child);
>> if (ret < 0) {
>
> I think that we need to make sure that "ret" is initialised to 0 at the
> beginning of the function. We should not have a case where the child
Hi Jon,
I didn't set ret to 0 at the beginning of the function since it is assigned the
return value of a previous call to of_property_read_u32(). So ret should be 0
when execution reaches the for loop.
> name does not match but who knows. Actually that raises another point,
> should we have an "else" clause at the end that WARNs on
> "unknown/unsupported child" device?
>
Actually I thought about it when I was writing that patch and then I decided to
not add a WARN for that case since nothing really fail in that case.
I mean if we want to check that a DT is well formed then I think we will need to
add much more checks and I don't know if is worth it.
But I don't have a strong opinion on this so if you want I can add it an send a v3.
>> of_node_put(child);
>> return ret;
>>
>
> Otherwise looks great.
>
> Cheers
> Jon
>
Best regards,
Javier
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