Commit a636ee7fb35b731ba2b331f6294e809bb6be09c8
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driver core: Early dev_name() support.
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@linux-sh.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Showing 2 changed files with 23 additions and 0 deletions Side-by-side Diff
drivers/base/platform.c
| ... | ... | @@ -1239,6 +1239,25 @@ |
| 1239 | 1239 | } |
| 1240 | 1240 | |
| 1241 | 1241 | if (match) { |
| 1242 | + /* | |
| 1243 | + * Set up a sensible init_name to enable | |
| 1244 | + * dev_name() and others to be used before the | |
| 1245 | + * rest of the driver core is initialized. | |
| 1246 | + */ | |
| 1247 | + if (!match->dev.init_name) { | |
| 1248 | + char buf[32]; | |
| 1249 | + | |
| 1250 | + if (match->id != -1) | |
| 1251 | + snprintf(buf, sizeof(buf), "%s.%d", | |
| 1252 | + match->name, match->id); | |
| 1253 | + else | |
| 1254 | + snprintf(buf, sizeof(buf), "%s", | |
| 1255 | + match->name); | |
| 1256 | + | |
| 1257 | + match->dev.init_name = kstrdup(buf, GFP_KERNEL); | |
| 1258 | + if (!match->dev.init_name) | |
| 1259 | + return -ENOMEM; | |
| 1260 | + } | |
| 1242 | 1261 | if (epdrv->pdrv->probe(match)) |
| 1243 | 1262 | pr_warning("%s: unable to probe %s early.\n", |
| 1244 | 1263 | class_str, match->name); |
include/linux/device.h
| ... | ... | @@ -451,6 +451,10 @@ |
| 451 | 451 | |
| 452 | 452 | static inline const char *dev_name(const struct device *dev) |
| 453 | 453 | { |
| 454 | + /* Use the init name until the kobject becomes available */ | |
| 455 | + if (dev->init_name) | |
| 456 | + return dev->init_name; | |
| 457 | + | |
| 454 | 458 | return kobject_name(&dev->kobj); |
| 455 | 459 | } |
| 456 | 460 |