12:46 a.m.
Hi Lina,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on pm/linux-next]
[also build test WARNING on linus/master v5.9 next-20201013]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/Lina-Iyer/Better-domain-idle-fro...
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: i386-randconfig-m021-20201013 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
smatch warnings:
drivers/base/power/domain_governor.c:269 default_power_down_ok() warn: always true
condition '(state_idx >= 0) => (0-u32max >= 0)'
drivers/base/power/domain_governor.c:269 default_power_down_ok() warn: always true
condition '(state_idx >= 0) => (0-u32max >= 0)'
drivers/base/power/domain_governor.c:277 default_power_down_ok() warn: unsigned
'state_idx' is never less than zero.
vim +269 drivers/base/power/domain_governor.c
245
246 /**
247 * default_power_down_ok - Default generic PM domain power off governor routine.
248 * @pd: PM domain to check.
249 *
250 * This routine must be executed under the PM domain's lock.
251 */
252 static bool default_power_down_ok(struct dev_pm_domain *pd)
253 {
254 struct generic_pm_domain *genpd = pd_to_genpd(pd);
255 struct gpd_link *link;
256 unsigned int state_idx;
257 ktime_t now = ktime_get();
258
259 /*
260 * Find the next wakeup from devices that can determine their own wakeup
261 * to find when the domain would wakeup and do it for every device down
262 * the hierarchy. It is not worth while to sleep if the state's residency
263 * cannot be met.
264 */
265 update_domain_next_wakeup(genpd, now);
266 state_idx = genpd->state_count - 1;
267 if (genpd->next_wakeup != KTIME_MAX) {
268 /* Let's find out the deepest domain idle state, the devices prefer */
269 while (state_idx >= 0) {
270 if
(next_wakeup_allows_state(genpd, state_idx, now)) {
271 genpd->max_off_time_changed = true;
272 break;
273 }
274 state_idx--;
275 }
276
277 if (state_idx < 0) {
278 state_idx = 0;
279 genpd->cached_power_down_ok = false;
280 goto done;
281 }
282 }
283
284 if (!genpd->max_off_time_changed) {
285 genpd->state_idx = genpd->cached_power_down_state_idx;
286 return genpd->cached_power_down_ok;
287 }
288
289 /*
290 * We have to invalidate the cached results for the parents, so
291 * use the observation that default_power_down_ok() is not
292 * going to be called for any parent until this instance
293 * returns.
294 */
295 list_for_each_entry(link, &genpd->child_links, child_node)
296 link->parent->max_off_time_changed = true;
297
298 genpd->max_off_time_ns = -1;
299 genpd->max_off_time_changed = false;
300 genpd->cached_power_down_ok = true;
301
302 /* Find a state to power down to, starting from the state
303 * determined by the next wakeup.
304 */
305 while (!__default_power_down_ok(pd, state_idx)) {
306 if (state_idx == 0) {
307 genpd->cached_power_down_ok = false;
308 break;
309 }
310 state_idx--;
311 }
312
313 done:
314 genpd->state_idx = state_idx;
315 genpd->cached_power_down_state_idx = genpd->state_idx;
316 return genpd->cached_power_down_ok;
317 }
318
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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org