lkml.org 
[lkml]   [2020]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RESEND PATCH v5 2/5] driver core: add deferring probe reason to devices_deferred property
    On Wed, Jun 24, 2020 at 01:41:24PM +0200, Andrzej Hajda wrote:
    > /sys/kernel/debug/devices_deferred property contains list of deferred devices.
    > This list does not contain reason why the driver deferred probe, the patch
    > improves it.
    > The natural place to set the reason is probe_err function introduced recently,
    > ie. if probe_err will be called with -EPROBE_DEFER instead of printk the message
    > will be attached to deferred device and printed when user read devices_deferred
    > property.
    >
    > Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
    > Reviewed-by: Mark Brown <broonie@kernel.org>
    > Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
    > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
    > ---
    > drivers/base/base.h | 3 +++
    > drivers/base/core.c | 10 ++++++----
    > drivers/base/dd.c | 21 ++++++++++++++++++++-
    > 3 files changed, 29 insertions(+), 5 deletions(-)
    >
    > diff --git a/drivers/base/base.h b/drivers/base/base.h
    > index 95c22c0f9036..93ef1c2f4c1f 100644
    > --- a/drivers/base/base.h
    > +++ b/drivers/base/base.h
    > @@ -93,6 +93,7 @@ struct device_private {
    > struct klist_node knode_class;
    > struct list_head deferred_probe;
    > struct device_driver *async_driver;
    > + char *deferred_probe_msg;
    > struct device *device;
    > u8 dead:1;
    > };
    > @@ -134,6 +135,8 @@ extern void device_release_driver_internal(struct device *dev,
    > extern void driver_detach(struct device_driver *drv);
    > extern int driver_probe_device(struct device_driver *drv, struct device *dev);
    > extern void driver_deferred_probe_del(struct device *dev);
    > +extern void __deferred_probe_set_msg(const struct device *dev,
    > + struct va_format *vaf);
    > static inline int driver_match_device(struct device_driver *drv,
    > struct device *dev)
    > {
    > diff --git a/drivers/base/core.c b/drivers/base/core.c
    > index ee9da66bff1b..2a96954d5460 100644
    > --- a/drivers/base/core.c
    > +++ b/drivers/base/core.c
    > @@ -3962,6 +3962,8 @@ define_dev_printk_level(_dev_info, KERN_INFO);
    > *
    > * This helper implements common pattern present in probe functions for error
    > * checking: print message if the error is not -EPROBE_DEFER and propagate it.
    > + * In case of -EPROBE_DEFER it sets defer probe reason, which can be checked
    > + * later by reading devices_deferred debugfs attribute.
    > * It replaces code sequence:
    > * if (err != -EPROBE_DEFER)
    > * dev_err(dev, ...);
    > @@ -3977,14 +3979,14 @@ int probe_err(const struct device *dev, int err, const char *fmt, ...)
    > struct va_format vaf;
    > va_list args;
    >
    > - if (err == -EPROBE_DEFER)
    > - return err;
    > -
    > va_start(args, fmt);
    > vaf.fmt = fmt;
    > vaf.va = &args;
    >
    > - dev_err(dev, "error %d: %pV", err, &vaf);
    > + if (err == -EPROBE_DEFER)
    > + __deferred_probe_set_msg(dev, &vaf);
    > + else
    > + dev_err(dev, "error %d: %pV", err, &vaf);
    >
    > va_end(args);
    >
    > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
    > index 9a1d940342ac..f44d26454b6a 100644
    > --- a/drivers/base/dd.c
    > +++ b/drivers/base/dd.c
    > @@ -27,6 +27,7 @@
    > #include <linux/async.h>
    > #include <linux/pm_runtime.h>
    > #include <linux/pinctrl/devinfo.h>
    > +#include <linux/slab.h>
    >
    > #include "base.h"
    > #include "power/power.h"
    > @@ -136,6 +137,8 @@ void driver_deferred_probe_del(struct device *dev)
    > if (!list_empty(&dev->p->deferred_probe)) {
    > dev_dbg(dev, "Removed from deferred list\n");
    > list_del_init(&dev->p->deferred_probe);
    > + kfree(dev->p->deferred_probe_msg);
    > + dev->p->deferred_probe_msg = NULL;
    > }
    > mutex_unlock(&deferred_probe_mutex);
    > }
    > @@ -211,6 +214,21 @@ void device_unblock_probing(void)
    > driver_deferred_probe_trigger();
    > }
    >
    > +/*
    > + * __deferred_probe_set_msg() - Set defer probe reason message for device
    > + */
    > +void __deferred_probe_set_msg(const struct device *dev, struct va_format *vaf)
    > +{
    > + const char *drv = dev_driver_string(dev);
    > +
    > + mutex_lock(&deferred_probe_mutex);
    > +
    > + kfree(dev->p->deferred_probe_msg);
    > + dev->p->deferred_probe_msg = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf);

    What about the device name? Don't you also want that?

    You want the same format that __dev_printk() outputs, please use that
    to be consistant with all other messages that drivers are spitting out.

    thanks,

    greg k-h

    \
     
     \ /
      Last update: 2020-06-24 14:35    [W:4.708 / U:0.784 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site