[PATCH 03/20] lightnvm: fix capabilities for 2.0 sysfs

[Javier Gonzalez]

> On 22 Feb 2018, at 12.10, Matias Bjørling <mb at lightnvm.io> wrote:
> 
> On 02/22/2018 11:25 AM, Javier Gonzalez wrote:
>>> On 22 Feb 2018, at 10.39, Matias Bjørling <mb at lightnvm.io> wrote:
>>> 
>>> On 02/22/2018 08:47 AM, Javier Gonzalez wrote:
>>>>> On 22 Feb 2018, at 08.28, Matias Bjørling <mb at lightnvm.io> wrote:
>>>>> 
>>>>>> On 02/21/2018 10:26 AM, Javier González wrote:
>>>>>> Both 1.2 and 2.0 specs define a field for media and controller
>>>>>> capabilities. Also, 1.2 defines a separate field dedicated to device
>>>>>> capabilities.
>>>>>> In 2.0 sysfs, this values have been mixed. Revert them to the right
>>>>>> value.
>>>>>> Signed-off-by: Javier González <javier at cnexlabs.com>
>>>>>> ---
>>>>>>  drivers/nvme/host/lightnvm.c | 18 +++++++++---------
>>>>>>  1 file changed, 9 insertions(+), 9 deletions(-)
>>>>>> diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
>>>>>> index 969bb874850c..598abba66f52 100644
>>>>>> --- a/drivers/nvme/host/lightnvm.c
>>>>>> +++ b/drivers/nvme/host/lightnvm.c
>>>>>> @@ -914,8 +914,8 @@ static ssize_t nvm_dev_attr_show(struct device *dev,
>>>>>>        if (strcmp(attr->name, "version") == 0) {
>>>>>>          return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->ver_id);
>>>>>> -    } else if (strcmp(attr->name, "capabilities") == 0) {
>>>>>> -        return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.cap);
>>>>>> +    } else if (strcmp(attr->name, "media_capabilities") == 0) {
>>>>>> +        return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mccap);
>>>>>>      } else if (strcmp(attr->name, "read_typ") == 0) {
>>>>>>          return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.trdt);
>>>>>>      } else if (strcmp(attr->name, "read_max") == 0) {
>>>>>> @@ -993,8 +993,8 @@ static ssize_t nvm_dev_attr_show_12(struct device *dev,
>>>>>>          return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.tbem);
>>>>>>      } else if (strcmp(attr->name, "multiplane_modes") == 0) {
>>>>>>          return scnprintf(page, PAGE_SIZE, "0x%08x\n", dev_geo->c.mpos);
>>>>>> -    } else if (strcmp(attr->name, "media_capabilities") == 0) {
>>>>>> -        return scnprintf(page, PAGE_SIZE, "0x%08x\n", dev_geo->c.mccap);
>>>>>> +    } else if (strcmp(attr->name, "capabilities") == 0) {
>>>>>> +        return scnprintf(page, PAGE_SIZE, "0x%08x\n", dev_geo->c.cap);
>>>>>>      } else if (strcmp(attr->name, "max_phys_secs") == 0) {
>>>>>>          return scnprintf(page, PAGE_SIZE, "%u\n", NVM_MAX_VLBA);
>>>>>>      } else {
>>>>>> @@ -1055,7 +1055,7 @@ static ssize_t nvm_dev_attr_show_20(struct device *dev,
>>>>>>    /* general attributes */
>>>>>>  static NVM_DEV_ATTR_RO(version);
>>>>>> -static NVM_DEV_ATTR_RO(capabilities);
>>>>>> +static NVM_DEV_ATTR_RO(media_capabilities);
>>>>>>    static NVM_DEV_ATTR_RO(read_typ);
>>>>>>  static NVM_DEV_ATTR_RO(read_max);
>>>>>> @@ -1080,12 +1080,12 @@ static NVM_DEV_ATTR_12_RO(prog_max);
>>>>>>  static NVM_DEV_ATTR_12_RO(erase_typ);
>>>>>>  static NVM_DEV_ATTR_12_RO(erase_max);
>>>>>>  static NVM_DEV_ATTR_12_RO(multiplane_modes);
>>>>>> -static NVM_DEV_ATTR_12_RO(media_capabilities);
>>>>>> +static NVM_DEV_ATTR_12_RO(capabilities);
>>>>>>  static NVM_DEV_ATTR_12_RO(max_phys_secs);
>>>>>>    static struct attribute *nvm_dev_attrs_12[] = {
>>>>>>      &dev_attr_version.attr,
>>>>>> -    &dev_attr_capabilities.attr,
>>>>>> +    &dev_attr_media_capabilities.attr,
>>>>>>        &dev_attr_vendor_opcode.attr,
>>>>>>      &dev_attr_device_mode.attr,
>>>>>> @@ -1108,7 +1108,7 @@ static struct attribute *nvm_dev_attrs_12[] = {
>>>>>>      &dev_attr_erase_typ.attr,
>>>>>>      &dev_attr_erase_max.attr,
>>>>>>      &dev_attr_multiplane_modes.attr,
>>>>>> -    &dev_attr_media_capabilities.attr,
>>>>>> +    &dev_attr_capabilities.attr,
>>>>>>      &dev_attr_max_phys_secs.attr,
>>>>>>        NULL,
>>>>>> @@ -1134,7 +1134,7 @@ static NVM_DEV_ATTR_20_RO(reset_max);
>>>>>>    static struct attribute *nvm_dev_attrs_20[] = {
>>>>>>      &dev_attr_version.attr,
>>>>>> -    &dev_attr_capabilities.attr,
>>>>>> +    &dev_attr_media_capabilities.attr,
>>>>>>        &dev_attr_groups.attr,
>>>>>>      &dev_attr_punits.attr,
>>>>> 
>>>>> With the mccap changes, it should make sense to keep the capabilities
>>>>> as is.
>>>> The change adds mccap, but sysfs points to cap, which is wrong. This
>>>> patch is needed. Otherwise, we change the name of mccap to cap, which
>>>> is _very_ confusing to people familiar to both specs. We can change
>>>> the name of mccap to cap in a future spec revision.
>>>> Javier
>>> 
>>> Think of the sysfs capabilities as an abstract value that defines generic capabilities. It is not directly tied to either 1.2 or 2.0.
>> I’m thinking about the user looking at sysfs and at the spec at the same time - I myself get confused when names don’t match.
>> Anyway, I’ll keep it the way it was and add a comment for clarification. Would that work for you?
> 
> That works. One may also wait until it is going to be used, e.g., when
> vector copy is implemented. Then it's natural to revisit.

Ok. Let's do that then. I'll drop the 2 patches then.

Javier
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