linux-kernel - Re: [PATCH v4 1/8] reset: modify the way reset lookup works for board files

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Date:   Fri, 23 Mar 2018 14:46:18 +0100
From:   Bartosz Golaszewski <bgolaszewski@...libre.com>
To:     Philipp Zabel <p.zabel@...gutronix.de>
Cc:     Bartosz Golaszewski <brgl@...ev.pl>, Sekhar Nori <nsekhar@...com>,
        Kevin Hilman <khilman@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Russell King <linux@...linux.org.uk>,
        David Lechner <david@...hnology.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Ohad Ben-Cohen <ohad@...ery.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        arm-soc <linux-arm-kernel@...ts.infradead.org>,
        linux-devicetree <devicetree@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>, linux-clk@...r.kernel.org,
        linux-remoteproc@...r.kernel.org
Subject: Re: [PATCH v4 1/8] reset: modify the way reset lookup works for board files

2018-03-23 14:43 GMT+01:00 Philipp Zabel <p.zabel@...gutronix.de>:
> On Fri, 2018-03-23 at 14:04 +0100, Bartosz Golaszewski wrote:
>> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
>>
>> Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
>> introduced reset control lookup mechanism for boards that still use
>> board files.
>>
>> The routine used to register lookup entries takes the corresponding
>> reset_controlled_dev structure as argument.
>>
>> It's been determined however that for the first user of this new
>> interface - davinci psc driver - it will be easier to register the
>> lookup entries using the reset controller device name.
>>
>> This patch changes the way lookup entries are added.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>
>> ---
>>  drivers/reset/core.c             | 38 +++++++++++++++++++++++++++++++-------
>>  include/linux/reset-controller.h | 14 ++++++++------
>>  2 files changed, 39 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
>> index 06fa4907afc4..f4a29c046995 100644
>> --- a/drivers/reset/core.c
>> +++ b/drivers/reset/core.c
>> @@ -153,12 +153,10 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>>
>>  /**
>>   * reset_controller_add_lookup - register a set of lookup entries
>> - * @rcdev: initialized reset controller device owning the reset line
>>   * @lookup: array of reset lookup entries
>>   * @num_entries: number of entries in the lookup array
>>   */
>> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
>> -                              struct reset_control_lookup *lookup,
>> +void reset_controller_add_lookup(struct reset_control_lookup *lookup,
>>                                unsigned int num_entries)
>>  {
>>       struct reset_control_lookup *entry;
>> @@ -168,13 +166,12 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
>>       for (i = 0; i < num_entries; i++) {
>>               entry = &lookup[i];
>>
>> -             if (!entry->dev_id) {
>> -                     pr_warn("%s(): reset lookup entry has no dev_id, skipping\n",
>> +             if (!entry->dev_id || !entry->provider) {
>> +                     pr_warn("%s(): reset lookup entry badly specified, skipping\n",
>>                               __func__);
>>                       continue;
>>               }
>>
>> -             entry->rcdev = rcdev;
>>               list_add_tail(&entry->list, &reset_lookup_list);
>>       }
>>       mutex_unlock(&reset_lookup_mutex);
>> @@ -526,11 +523,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
>>  }
>>  EXPORT_SYMBOL_GPL(__of_reset_control_get);
>>
>> +static struct reset_controller_dev *
>> +__reset_controller_by_name(const char *name)
>> +{
>> +     struct reset_controller_dev *rcdev;
>> +
>> +     lockdep_assert_held(&reset_list_mutex);
>> +
>> +     list_for_each_entry(rcdev, &reset_controller_list, list) {
>> +             if (!rcdev->dev)
>> +                     continue;
>> +
>> +             if (!strcmp(name, dev_name(rcdev->dev)))
>> +                     return rcdev;
>> +     }
>> +
>> +     return NULL;
>> +}
>> +
>>  static struct reset_control *
>>  __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>>                               bool shared, bool optional)
>>  {
>>       const struct reset_control_lookup *lookup;
>> +     struct reset_controller_dev *rcdev;
>>       const char *dev_id = dev_name(dev);
>>       struct reset_control *rstc = NULL;
>>
>> @@ -547,7 +563,15 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
>>                   ((con_id && lookup->con_id) &&
>>                    !strcmp(con_id, lookup->con_id))) {
>>                       mutex_lock(&reset_list_mutex);
>> -                     rstc = __reset_control_get_internal(lookup->rcdev,
>> +                     rcdev = __reset_controller_by_name(lookup->provider);
>> +                     if (!rcdev) {
>> +                             mutex_unlock(&reset_list_mutex);
>> +                             mutex_unlock(&reset_lookup_mutex);
>> +                             /* Reset provider may not be ready yet. */
>> +                             return -EPROBE_DEFER;
>
> Thanks, I've applied this patch to reset/next with the following change:
>
> -                               return -EPROBE_DEFER;
> +                               return ERR_PTR(-EPROBE_DEFER);
>
> regards
> Philipp

Oops, thanks for spotting that.

Thanks,
Bart