2022-04-21 06:42:36

by Adam Wujek

[permalink] [raw]
Subject: Re: [PATCH 2/2] hwmon: (pmbus) add MFR_* registers to debugfs

------- Original Message -------
On Wednesday, April 20th, 2022 at 16:15, Guenter Roeck <[email protected]> wrote:


>
>
> On 4/20/22 06:58, wujek dev wrote:
>
> > ------- Original Message -------
> > On Wednesday, April 20th, 2022 at 15:53, Guenter Roeck [email protected] wrote:
> >
> > > On 4/20/22 05:22, Adam Wujek wrote:
> > >
> > > > Add registers to debugfs:
> > > > PMBUS_MFR_ID
> > > > PMBUS_MFR_MODEL
> > > > PMBUS_MFR_REVISION
> > > > PMBUS_MFR_LOCATION
> > > > PMBUS_MFR_DATE
> > > > PMBUS_MFR_SERIAL
> > > >
> > > > Signed-off-by: Adam Wujek [email protected]
> > >
> > > Where is patch 1/2, and why did you resend this patch ?
> >
> > There should be no "1/2" since this and the second patch are unrelated.
> > I resend it because I rebased it on master.
>
> Please provide change logs and version your patches in the future.
ok, thank you for your patience.
>
> > Adam
> >
> > > Guenter
> > >
> > > > ---
> > > > drivers/hwmon/pmbus/pmbus_core.c | 84 ++++++++++++++++++++++++++++++++
> > > > 1 file changed, 84 insertions(+)
> > > >
> > > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> > > > index 0af7a3d74f47..1dc186780ccf 100644
> > > > --- a/drivers/hwmon/pmbus/pmbus_core.c
> > > > +++ b/drivers/hwmon/pmbus/pmbus_core.c
> > > > @@ -2625,6 +2625,30 @@ static int pmbus_debugfs_get_status(void *data, u64 *val)
> > > > DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_status, pmbus_debugfs_get_status,
> > > > NULL, "0x%04llx\n");
> > > >
> > > > +static ssize_t pmbus_debugfs_mfr_read(struct file *file, char __user *buf,
> > > > + size_t count, loff_t *ppos)
> > > > +{
> > > > + int rc;
> > > > + struct pmbus_debugfs_entry *entry = file->private_data;
> > > > + char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
> > > > +
> > > > + rc = i2c_smbus_read_block_data(entry->client, entry->reg, data);
> > > > + if (rc < 0)
> > > > + return rc;
> > > > +
> > > > + data[rc] = '\n';
> > > > + rc += 2;
>
>
> Why +2 ?
>
Copied from another driver.
+1 due to '\n'
+1 due to NULL character (smbus block transfer does not include it in the length)
Explanation included in v3 patch.
> > > > +
> > > > + return simple_read_from_buffer(buf, count, ppos, data, rc);
> > > > +}
> > > > +
> > > > +static const struct file_operations pmbus_debugfs_ops_mfr = {
> > > > + .llseek = noop_llseek,
> > > > + .read = pmbus_debugfs_mfr_read,
> > > > + .write = NULL,
> > > > + .open = simple_open,
> > > > +};
> > > > +
> > > > static int pmbus_debugfs_get_pec(void *data, u64 *val)
> > > > {
> > > > struct i2c_client *client = data;
> > > > @@ -2801,6 +2825,66 @@ static int pmbus_init_debugfs(struct i2c_client *client,
> > > > &entries[idx++],
> > > > &pmbus_debugfs_ops);
> > > > }
> > > > +
> > > > + if (pmbus_check_byte_register(client, i, PMBUS_MFR_ID)) {
> > > > + entries[idx].client = client;
> > > > + entries[idx].page = i;
> > > > + entries[idx].reg = PMBUS_MFR_ID;
> > > > + scnprintf(name, PMBUS_NAME_SIZE, "mfr%d_id", i);
> > > > + debugfs_create_file(name, 0444, data->debugfs,
> > > > + &entries[idx++],
> > > > + &pmbus_debugfs_ops_mfr);
> > > > + }
>
>
> You are adding several debugfs entries without increasing the size
> of the entries array. That means that up to 16 debugfs entries are
> now created into an array of size 10. That won't work.
You're right, I just sent another patch.

Adam
>
> Guenter


2022-04-22 21:45:21

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH 2/2] hwmon: (pmbus) add MFR_* registers to debugfs

On 4/20/22 08:51, wujek dev wrote:
> ------- Original Message -------
> On Wednesday, April 20th, 2022 at 16:15, Guenter Roeck <[email protected]> wrote:
>
>
>>
>>
>> On 4/20/22 06:58, wujek dev wrote:
>>
>>> ------- Original Message -------
>>> On Wednesday, April 20th, 2022 at 15:53, Guenter Roeck [email protected] wrote:
>>>
>>>> On 4/20/22 05:22, Adam Wujek wrote:
>>>>
>>>>> Add registers to debugfs:
>>>>> PMBUS_MFR_ID
>>>>> PMBUS_MFR_MODEL
>>>>> PMBUS_MFR_REVISION
>>>>> PMBUS_MFR_LOCATION
>>>>> PMBUS_MFR_DATE
>>>>> PMBUS_MFR_SERIAL
>>>>>
>>>>> Signed-off-by: Adam Wujek [email protected]
>>>>
>>>> Where is patch 1/2, and why did you resend this patch ?
>>>
>>> There should be no "1/2" since this and the second patch are unrelated.
>>> I resend it because I rebased it on master.
>>
>> Please provide change logs and version your patches in the future.
> ok, thank you for your patience.
>>
>>> Adam
>>>
>>>> Guenter
>>>>
>>>>> ---
>>>>> drivers/hwmon/pmbus/pmbus_core.c | 84 ++++++++++++++++++++++++++++++++
>>>>> 1 file changed, 84 insertions(+)
>>>>>
>>>>> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
>>>>> index 0af7a3d74f47..1dc186780ccf 100644
>>>>> --- a/drivers/hwmon/pmbus/pmbus_core.c
>>>>> +++ b/drivers/hwmon/pmbus/pmbus_core.c
>>>>> @@ -2625,6 +2625,30 @@ static int pmbus_debugfs_get_status(void *data, u64 *val)
>>>>> DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_status, pmbus_debugfs_get_status,
>>>>> NULL, "0x%04llx\n");
>>>>>
>>>>> +static ssize_t pmbus_debugfs_mfr_read(struct file *file, char __user *buf,
>>>>> + size_t count, loff_t *ppos)
>>>>> +{
>>>>> + int rc;
>>>>> + struct pmbus_debugfs_entry *entry = file->private_data;
>>>>> + char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
>>>>> +
>>>>> + rc = i2c_smbus_read_block_data(entry->client, entry->reg, data);
>>>>> + if (rc < 0)
>>>>> + return rc;
>>>>> +
>>>>> + data[rc] = '\n';
>>>>> + rc += 2;
>>
>>
>> Why +2 ?
>>
> Copied from another driver.
> +1 due to '\n'
> +1 due to NULL character (smbus block transfer does not include it in the length)
> Explanation included in v3 patch.

"copied from another driver" is not really a good argument.
That other driver might just be buggy.

What do you see in userspace when you read the data ? A string that ends with
"\n\0" ? If so, does the "\0" at the end add any value ?

Guenter