From: Andrzej Hajda <a.hajda@samsung.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Javier Martinez Canillas <javierm@redhat.com>,
linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH 1/3] driver core: add probe_err log helper
Date: Tue, 16 Oct 2018 14:55:41 +0200 [thread overview]
Message-ID: <20181016125543eucas1p1f23b3482179a9cd465f509e0abf782c1~eGAecmAv93038330383eucas1p1j@eucas1p1.samsung.com> (raw)
In-Reply-To: <605bd00e-ed0d-4259-bdc3-1784b2b3b16a@samsung.com>
On 16.10.2018 13:29, Andrzej Hajda wrote:
> On 16.10.2018 13:01, Andy Shevchenko wrote:
>> On Tue, Oct 16, 2018 at 10:22 AM Andrzej Hajda <a.hajda@samsung.com> wrote:
>>> During probe every time driver gets resource it should usually check for error
>>> printk some message if it is not -EPROBE_DEFER and return the error. This
>>> pattern is simple but requires adding few lines after any resource acquisition
>>> code, as a result it is often omited or implemented only partially.
>>> probe_err helps to replace such code seqences with simple call, so code:
>>> if (err != -EPROBE_DEFER)
>>> dev_err(dev, ...);
>>> return err;
>>> becomes:
>>> return probe_err(dev, err, ...);
>>>
>>> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
>>> ---
>>> drivers/base/core.c | 37 +++++++++++++++++++++++++++++++++++++
>>> include/linux/device.h | 2 ++
>>> 2 files changed, 39 insertions(+)
>>>
>>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>>> index 04bbcd779e11..23fabefb217a 100644
>>> --- a/drivers/base/core.c
>>> +++ b/drivers/base/core.c
>>> @@ -3067,6 +3067,43 @@ define_dev_printk_level(_dev_info, KERN_INFO);
>>>
>>> #endif
>>>
>>> +/**
>>> + * probe_err - probe error check and log helper
>>> + * @dev: the pointer to the struct device
>>> + * @err: error value to test
>>> + * @fmt: printf-style format string
>>> + * @...: arguments as specified in the format string
>>> + *
>>> + * This helper implements common pattern present in probe functions for error
>>> + * checking: print message if the error is not -EPROBE_DEFER and propagate it.
>>> + * It replaces code sequence:
>>> + * if (err != -EPROBE_DEFER)
>>> + * dev_err(dev, ...);
>>> + * return err;
>>> + * with
>>> + * return probe_err(dev, err, ...);
>>> + *
>>> + * Returns @err.
>>> + *
>>> + */
>>> +int probe_err(const struct device *dev, int err, const char *fmt, ...)
>>> +{
>>> + struct va_format vaf;
>>> + va_list args;
>>> +
>>> + if (err != -EPROBE_DEFER) {
>> Why not
>>
>> if (err == ...)
>> return err;
>>
>> ...
>> return err;
>>
>> ?
>>
>> Better to read, better to maintain. No?
> Yes, anyway next patch will re-factor it anyway.
>
>>> + va_start(args, fmt);
>>> +
>>> + vaf.fmt = fmt;
>>> + vaf.va = &args;
>>> +
>>> + __dev_printk(KERN_ERR, dev, &vaf);
>> It would be nice to print an error code as well, wouldn't it?
> Hmm, on probe fail error is printed anyway (with exception of
> EPROBE_DEFER, ENODEV and ENXIO):
> "probe of %s failed with error %d\n"
> On the other side currently some drivers prints the error code anyway
> via dev_err or similar, so I guess during conversion to probe_err it
> should be removed then.
>
> If we add error code to probe_err is it OK to report it this way?
> dev_err(dev, "%V, %d\n", &vaf, err);
Ups, I forgot that message passed to probe_err will contain already
newline character.
So the err must be before message passed to probe_err, for example:
dev_err(dev, "err=%d: %V\n", err, &vaf);
Is it OK? Or better leave this part of the patch as is?
Regards
Andrzej
>
> Regards
> Andrzej
>
>>> + va_end(args);
>>> + }
>>> +
>>> + return err;
>>> +}
>>> +
>>> static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
>>> {
>>> return fwnode && !IS_ERR(fwnode->secondary);
>>> diff --git a/include/linux/device.h b/include/linux/device.h
>>> index 90224e75ade4..06c2c797d132 100644
>>> --- a/include/linux/device.h
>>> +++ b/include/linux/device.h
>>> @@ -1577,6 +1577,8 @@ do { \
>>> WARN_ONCE(condition, "%s %s: " format, \
>>> dev_driver_string(dev), dev_name(dev), ## arg)
>>>
>>> +int probe_err(const struct device *dev, int err, const char *fmt, ...);
>>> +
>>> /* Create alias, so I can be autoloaded. */
>>> #define MODULE_ALIAS_CHARDEV(major,minor) \
>>> MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
>>> --
>>> 2.18.0
>>>
next prev parent reply other threads:[~2018-10-16 12:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20181016072248eucas1p18943ce87e084797cd597afd4edb65a65@eucas1p1.samsung.com>
2018-10-16 7:22 ` [PATCH 0/3] driver core: add probe error check helper Andrzej Hajda
[not found] ` <CGME20181016072249eucas1p2303b8c06a9f7c839a971fe065b0c752e@eucas1p2.samsung.com>
2018-10-16 7:22 ` [PATCH 1/3] driver core: add probe_err log helper Andrzej Hajda
2018-10-16 9:32 ` Javier Martinez Canillas
2018-10-16 10:27 ` Mark Brown
2018-10-16 11:09 ` Greg Kroah-Hartman
2018-10-16 11:01 ` Andy Shevchenko
2018-10-16 11:29 ` Andrzej Hajda
[not found] ` <605bd00e-ed0d-4259-bdc3-1784b2b3b16a@samsung.com>
2018-10-16 12:55 ` Andrzej Hajda [this message]
2018-10-16 13:55 ` Andy Shevchenko
[not found] ` <CGME20181017085832eucas1p23dbb86230149a13634b8a091c3b1301f@eucas1p2.samsung.com>
2018-10-17 8:58 ` [PATCH v2 " Andrzej Hajda
2018-10-17 9:56 ` Mark Brown
2018-10-17 11:30 ` Andy Shevchenko
2018-10-17 11:49 ` Greg Kroah-Hartman
2018-10-17 11:29 ` [PATCH " Russell King - ARM Linux
2018-10-17 11:33 ` Andy Shevchenko
[not found] ` <CGME20181017132209eucas1p1d23615adc15663caaffb3c117dc61151@eucas1p1.samsung.com>
2018-10-17 13:22 ` [PATCH v3 1/4] " Andrzej Hajda
2018-10-18 1:45 ` [PATCH 1/3] " Joe Perches
[not found] ` <CGME20181016072249eucas1p28855602564eb74a771fe521712962680@eucas1p2.samsung.com>
2018-10-16 7:22 ` [PATCH 2/3] driver core: add deferring probe reason to devices_deferred property Andrzej Hajda
2018-10-16 9:25 ` Mark Brown
2018-10-16 9:47 ` Javier Martinez Canillas
2018-10-16 13:42 ` Andy Shevchenko
[not found] ` <CGME20181017085952eucas1p2ff93b96d300aab2dc70b97bf266978ab@eucas1p2.samsung.com>
2018-10-17 8:59 ` [PATCH v2 " Andrzej Hajda
2018-10-17 11:35 ` Andy Shevchenko
[not found] ` <CGME20181017132404eucas1p2a413f6853af8f11a874650b6289d56cf@eucas1p2.samsung.com>
2018-10-17 13:24 ` [PATCH v3 2/4] " Andrzej Hajda
2018-10-17 14:17 ` Andy Shevchenko
[not found] ` <CGME20181018064916eucas1p22f03a19eb09cecdb0061dc5a4bf99ce6@eucas1p2.samsung.com>
2018-10-18 6:49 ` [PATCH v4 2/3] " Andrzej Hajda
[not found] ` <CGME20181016072250eucas1p1a763670c8509d20a6e6847eadb246817@eucas1p1.samsung.com>
2018-10-16 7:22 ` [PATCH 3/3] drivers: use probe_err function in obvious cases Andrzej Hajda
2018-10-16 9:52 ` Javier Martinez Canillas
2018-10-16 13:51 ` Andy Shevchenko
2018-10-17 9:10 ` Andrzej Hajda
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