On Mon, 2021-01-11 at 09:27 +0800, Can Guo wrote: > > > > If accessing sysfs nodes, which triggers a UFS UPIU request to > > read/write UFS device descriptors during shutdown flow, there is > > only > > one issue that sysfs node access failure since UFS device and LINK > > has > > been shutdown. Strictly speaking, the failure comes after > > ufshcd_set_dev_pwr_mode(). > > > > __ufshcd_query_descriptor: opcode 0x01 for idn 0 failed, index > > 0, > > err = -11 > > You misunderstood it again. You are expecting a simple query cmd > error. > But what really matters are NoC issues[1] and OCP[2]. And > while/after > UFS > shutting down, either of them may happen. > > [1] When a un-clocked register access issue happens, we call it a > NoC > issue, > meaning you are tring to access a register when clocks are disabled. > This > leads to system CRASH. > OK, let it simple, share this kind of crash log becuase of access sysfs node in the shutdown flow. > [2] OCP is over current protection. While UFS shutting down, you may > have put UFS regulators to LPM. After that, if you are still trying > to > talk to UFS, OCP can happen on VCCQ/VCCQ2. This leads to system > CRASH > too. the same as above, share the crash log. > > > > > Since the shutdown is oneway process, this failure is not big > > issue. If > > you meant to avoid this failure for unsafe shutdown, I agree with > > you, > > But for the race issue, I don't know. > > > > Easy for you to say. System crash is a big issue to any SoC vendors > I > belive. > indeed, crash is serious issue, share the log. Thanks, Bean > Can Guo.
