[PATCH] driver core: Early dev_name() support.
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From: Paul Mundt on 9 Mar 2010 02:00 Presently early platform devices suffer from the fact they are unable to use dev_xxx() calls early on due to dev_name() and others being unavailable at the time ->probe() is called. This implements early init_name construction from the matched name/id pair following the semantics of the late device/driver match. As a result, matched IDs (inclusive of requested ones) are preserved when the handoff from the early platform code happens at kobject initialization time. Since we still require kmalloc slabs to be available at this point, using kstrdup() for establishing the init_name works fine. This subsequently needs to be tested from dev_name() prior to the init_name being cleared by the driver core. We don't kfree() since others will already have a handle on the string long before the kobject initialization takes place. This is also needed to permit drivers to use the clock framework early, without having to manually construct their own device IDs from the match id/name pair locally (needed by the early console and timer code on sh and arm). Signed-off-by: Paul Mundt <lethal(a)linux-sh.org> --- drivers/base/platform.c | 19 +++++++++++++++++++ include/linux/device.h | 4 ++++ 2 files changed, 23 insertions(+) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 58efaf2..bc38f63 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1181,6 +1181,25 @@ static int __init early_platform_driver_probe_id(char *class_str, } if (match) { + /* + * Set up a sensible init_name to enable + * dev_name() and others to be used before the + * rest of the driver core is initialized. + */ + if (!match->dev.init_name) { + char buf[32]; + + if (match->id != -1) + snprintf(buf, sizeof(buf), "%s.%d", + match->name, match->id); + else + snprintf(buf, sizeof(buf), "%s", + match->name); + + match->dev.init_name = kstrdup(buf, GFP_KERNEL); + if (!match->dev.init_name) + return -ENOMEM; + } if (epdrv->pdrv->probe(match)) pr_warning("%s: unable to probe %s early.\n", class_str, match->name); diff --git a/include/linux/device.h b/include/linux/device.h index b30527d..3af5bce 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -432,6 +432,10 @@ struct device { static inline const char *dev_name(const struct device *dev) { + /* Use the init name until the kobject becomes available */ + if (dev->init_name) + return dev->init_name; + return kobject_name(&dev->kobj); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |