/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 dev_err_probe function introduced recently, ie. if dev_err_probe will be called with -EPROBE_DEFER instead of printk the message will be attached to a deferred device and printed when user reads 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 Reviewed-by: Rafael J. Wysocki rafael@kernel.org --- v8: - improved commit message --- drivers/base/base.h | 3 +++ drivers/base/core.c | 8 ++++++-- drivers/base/dd.c | 23 ++++++++++++++++++++++- 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/base/base.h b/drivers/base/base.h index 95c22c0f9036..6954fccab3d7 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_reason; 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 device_set_deferred_probe_reson(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 3a827c82933f..fee047f03681 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3963,6 +3963,8 @@ define_dev_printk_level(_dev_info, KERN_INFO); * This helper implements common pattern present in probe functions for error * checking: print debug or error message depending if the error value is * -EPROBE_DEFER and propagate error upwards. + * In case of -EPROBE_DEFER it sets also 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, ...); @@ -3984,10 +3986,12 @@ int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) vaf.fmt = fmt; vaf.va = &args;

- if (err != -EPROBE_DEFER) + if (err != -EPROBE_DEFER) { dev_err(dev, "error %d: %pV", err, &vaf); - else + } else { + device_set_deferred_probe_reson(dev, &vaf); dev_dbg(dev, "error %d: %pV", err, &vaf); + }

va_end(args);

diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 9a1d940342ac..dd5683b61f74 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_reason); + dev->p->deferred_probe_reason = NULL; } mutex_unlock(&deferred_probe_mutex); } @@ -211,6 +214,23 @@ void device_unblock_probing(void) driver_deferred_probe_trigger(); }

+/** + * device_set_deferred_probe_reson() - Set defer probe reason message for device + * @dev: the pointer to the struct device + * @vaf: the pointer to va_format structure with message + */ +void device_set_deferred_probe_reson(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_reason); + dev->p->deferred_probe_reason = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf); + + mutex_unlock(&deferred_probe_mutex); +} + /* * deferred_devs_show() - Show the devices in the deferred probe pending list. */ @@ -221,7 +241,8 @@ static int deferred_devs_show(struct seq_file *s, void *data) mutex_lock(&deferred_probe_mutex);

list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe) - seq_printf(s, "%s\n", dev_name(curr->device)); + seq_printf(s, "%s\t%s", dev_name(curr->device), + curr->device->p->deferred_probe_reason ?: "\n");

mutex_unlock(&deferred_probe_mutex);

In case of error during resource acquisition driver should print error message only in case it is not deferred probe, using dev_err_probe helper solves the issue. Moreover it records defer probe reason for debugging.

Signed-off-by: Andrzej Hajda a.hajda@samsung.com Reviewed-by: Neil Armstrong narmstrong@baylibre.com --- drivers/gpu/drm/bridge/sil-sii8620.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c index 92acd336aa89..389c1f029774 100644 --- a/drivers/gpu/drm/bridge/sil-sii8620.c +++ b/drivers/gpu/drm/bridge/sil-sii8620.c @@ -2299,10 +2299,9 @@ static int sii8620_probe(struct i2c_client *client, INIT_LIST_HEAD(&ctx->mt_queue);

ctx->clk_xtal = devm_clk_get(dev, "xtal"); - if (IS_ERR(ctx->clk_xtal)) { - dev_err(dev, "failed to get xtal clock from DT\n"); - return PTR_ERR(ctx->clk_xtal); - } + if (IS_ERR(ctx->clk_xtal)) + return dev_err_probe(dev, PTR_ERR(ctx->clk_xtal), + "failed to get xtal clock from DT\n");

if (!client->irq) { dev_err(dev, "no irq provided\n"); @@ -2313,16 +2312,14 @@ static int sii8620_probe(struct i2c_client *client, sii8620_irq_thread, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "sii8620", ctx); - if (ret < 0) { - dev_err(dev, "failed to install IRQ handler\n"); - return ret; - } + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to install IRQ handler\n");

ctx->gpio_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); - if (IS_ERR(ctx->gpio_reset)) { - dev_err(dev, "failed to get reset gpio from DT\n"); - return PTR_ERR(ctx->gpio_reset); - } + if (IS_ERR(ctx->gpio_reset)) + return dev_err_probe(dev, PTR_ERR(ctx->gpio_reset), + "failed to get reset gpio from DT\n");

ctx->supplies[0].supply = "cvcc10"; ctx->supplies[1].supply = "iovcc18";

This is AD-HOC script, it should nt be merged.

Signed-off-by: Andrzej Hajda a.hajda@samsung.com --- probe_err.cocci | 247 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 247 insertions(+) create mode 100644 probe_err.cocci

diff --git a/probe_err.cocci b/probe_err.cocci new file mode 100644 index 000000000000..0ef9a9b4c9bc --- /dev/null +++ b/probe_err.cocci @@ -0,0 +1,247 @@ +virtual context +virtual patch + +@initialize:python@ +@@ + +import re + +@@ +expression err, dev; +constant char [] fmt; +expression list args; +@@ + +- if (err != -EPROBE_DEFER) { dev_err(dev, fmt, args); } ++ dev_err_probe(dev, err, fmt, args); + +@@ +expression ptr, dev; +constant char [] fmt; +expression list args; +@@ + +- if (ptr != ERR_PTR(-EPROBE_DEFER)) { dev_err(dev, fmt, args); } ++ dev_err_probe(dev, PTR_ERR(ptr), fmt, args); + +@@ +expression e, dev; +identifier err; +identifier fget =~ "^(devm_)?(clk_get|gpiod_get|gpiod_get_optional|gpiod_get_index|gpiod_get_index_optional|regulator_get|regulator_get_optional|reset_control_get|reset_control_get_exclusive|reset_control_get_shared|phy_get|pinctrl_get|iio_channel_get|pwm_get)$"; +identifier flog =~ "^(dev_err|dev_warn|dev_info)$"; +expression list args; +@@ + e = fget(...); + if (IS_ERR(e)) { +( + err = PTR_ERR(e); +- flog(dev, args); ++ dev_err_probe(dev, err, args); +| +- flog(dev, args); ++ dev_err_probe(dev, PTR_ERR(e), args); +) + ... + } + +@@ +expression dev; +identifier err; +identifier fget =~ "^(devm_)?(request_irq|request_threaded_irq|regulator_bulk_get)$"; +identifier flog =~ "^(dev_err|dev_warn|dev_info)$"; +expression list args; +@@ + err = fget(...); + if ( ( err | err < 0 ) ) { + ... +- flog(dev, args); ++ dev_err_probe(dev, err, args); + ... + } + +@catch_no_nl@ +expression dev, err; +constant char [] fmt !~ "\n$"; +@@ + dev_err_probe(dev, err, fmt, ...) + +@script:python add_nl depends on catch_no_nl@ +fmt << catch_no_nl.fmt; +nfmt; +@@ +print "add_nl " + fmt +coccinelle.nfmt = fmt[:-1] + '\n"'; + +@fix_no_nl depends on catch_no_nl@ +constant char [] catch_no_nl.fmt; +identifier add_nl.nfmt; +@@ +- fmt ++ nfmt + +@catch_fmt@ +expression err, dev; +expression fmt; +position p; +@@ + + dev_err_probe@p(dev, err, fmt, ..., ( (int)err | err ) ) + +@script:python trim_fmt@ +fmt << catch_fmt.fmt; +new_fmt; +@@ + +tmp = fmt +tmp = re.sub('failed: irq request (IRQ: %d, error :%d)', 'irq request %d', tmp) +tmp = re.sub('Error %l?[di] ', 'Error ', tmp) +tmp = re.sub(' as irq = %d\\n', ', bad irq\\n', tmp) +tmp = re.sub('[:,]? ?((ret|err|with|error)[ =]?)?%l?[di].?\\n', '\\n', tmp) +tmp = re.sub(' ?(((err|ret|error)\s*=?\s*)?%l?[diu])[!.]?\\n', '\\n', tmp) + +assert tmp != fmt, "cannot trim_fmt in: " + fmt +print "trim_fmt " + fmt + " " + tmp +coccinelle.new_fmt = tmp + +@fix_fmt@ +expression err, err1, dev; +expression fmt; +expression list l; +identifier trim_fmt.new_fmt; +position catch_fmt.p; +@@ + +- dev_err_probe@p(dev, err, fmt, l, err1) ++ dev_err_probe(dev, err, new_fmt, l) + +@err_ass1@ +identifier err; +expression dev, ptr; +expression list args; +@@ + +- err = PTR_ERR(ptr); +- dev_err_probe(dev, err, args); +- return ERR_PTR(err); ++ dev_err_probe(dev, PTR_ERR(ptr), args); ++ return ERR_CAST(ptr); + +@err_ass2@ +identifier err, f1, f2; +expression dev, e; +expression list args; +@@ +- err = PTR_ERR(e); +- dev_err_probe(dev, err, args); +( +| + f1(...); +| + f1(...); + f2(...); +) +- return err; ++ return dev_err_probe(dev, PTR_ERR(e), args); + +@@ +identifier err; +expression dev, e; +expression list args; +@@ + +- int err = e; +- dev_err_probe(dev, err, args); +- return err; ++ return dev_err_probe(dev, e, args); + +@@ +expression err, dev; +expression list args; +@@ + +- dev_err_probe(dev, err, args); +- return err; ++ return dev_err_probe(dev, err, args); + +@@ +expression err, dev, ptr; +expression list args; +@@ + +- dev_err_probe(dev, PTR_ERR(ptr), args); + err = PTR_ERR(ptr); ++ dev_err_probe(dev, err, args); + +@@ +expression e; +expression list args; +statement s, s1; +@@ + +// without s1 spatch generates extra empty line after s +- if (e) { return dev_err_probe(args); } else s s1 ++ if (e) return dev_err_probe(args); s s1 + +@@ +expression e; +expression list args; +@@ + +- if (e) { return dev_err_probe(args); } ++ if (e) return dev_err_probe(args); + +@@ +expression e, s, v; +expression list args; +@@ + +- if (e == v) { s; } else { return dev_err_probe(args); } ++ if (e != v) return dev_err_probe(args); s; + +@err_ass3@ +identifier err; +expression dev, ptr; +expression list args; +@@ + +- err = PTR_ERR_OR_ZERO(ptr); +- if (err) return dev_err_probe(dev, err, args); ++ if (IS_ERR(ptr)) return dev_err_probe(dev, PTR_ERR(ptr), args); + +@@ +expression dev, ptr; +expression list args; +@@ + +- DROP_probe_err(dev, PTR_ERR(ptr), args) ++ probe_err(dev, ptr, args) + +@@ +identifier err_ass1.err; +expression e; +identifier f =~ "^(dev_err_probe|probe_err_ptr)$"; +@@ +- ( int err; | int err = e; ) + <+... when != err + f + ...+> + +@@ +identifier err_ass2.err; +expression e; +identifier f =~ "^(dev_err_probe|probe_err_ptr)$"; +@@ +- ( int err; | int err = e; ) + <+... when != err + f + ...+> + +@@ +identifier err_ass3.err; +expression e; +identifier f =~ "^(dev_err_probe|probe_err_ptr)$"; +@@ +- ( int err; | int err = e; ) + <+... when != err + f + ...+>