On 11/09/23 09:32, Kiwoong Kim wrote: >>>> ufs: poll HCS.UCRDY before issuing a UIC command >>> >>> [ 4671.226480] [3: kworker/u20:29:17140] BUG: scheduling while atomic: >>> kworker/u20:29/17140/0x00000002 >>> .. >>> [ 4671.228723] [3: kworker/u20:29:17140] panic+0x16c/0x388 [ >>> 4671.228745] [3: kworker/u20:29:17140] check_panic_on_warn+0x60/0x94 >>> [ 4671.228764] [3: kworker/u20:29:17140] __schedule_bug+0x6c/0x94 [ >>> 4671.228786] [3: kworker/u20:29:17140] __schedule+0x6f4/0xa64 [ >>> 4671.228806] [3: kworker/u20:29:17140] schedule+0x7c/0xe8 [ >>> 4671.228824] [3: kworker/u20:29:17140] >>> schedule_hrtimeout_range_clock+0x98/0x114 >>> [ 4671.228841] [3: kworker/u20:29:17140] >>> schedule_hrtimeout_range+0x14/0x24 >>> [ 4671.228856] [3: kworker/u20:29:17140] usleep_range_state+0x60/0x94 >>> [ 4671.228871] [3: kworker/u20:29:17140] >>> __ufshcd_send_uic_cmd+0xa0/0x1c4 [ 4671.228893] [3: >>> kworker/u20:29:17140] ufshcd_uic_pwr_ctrl+0x15c/0x390 [ 4671.228908] >>> [3: kworker/u20:29:17140] ufshcd_uic_hibern8_enter+0x9c/0x25c >>> [ 4671.228922] [3: kworker/u20:29:17140] >>> ufshcd_link_state_transition+0x34/0xb0 >>> [ 4671.228939] [3: kworker/u20:29:17140] >>> __ufshcd_wl_suspend+0x3f0/0x4b4 >> >> Do you know what is in that path that makes it an atomic context? > > Hi, > This made that. > > static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd) > .. > bool reenable_intr = false; > > mutex_lock(&hba->uic_cmd_mutex); <<<< It is OK to schedule while holding a mutex. Are you sure this is the problem? > > > At first, I was willing to post together w/ the following patch but I've got a suggestion to split the patch set because of different topic and I split the patch set. > - This patch removes the mutex, so it can fix the issue. > https://lore.kernel.org/linux-scsi/1694051306-172962-1-git-send-email-kwmad.kim@xxxxxxxxxxx/ > > > But now I'm thinking again that simply removing the mutex could hurt atomicity of UIC command process > that the original code intended for the first time. > So I think this polling UCRDY should be modified rather than applying removal of the mutex. > > >
