On Tue, Jul 06, 2021 at 11:35:44AM +0200, Sean Nyekjaer wrote:

On Mon, Jul 05, 2021 at 08:58:38AM +0200, Sean Nyekjaer wrote:

quoted

Hi Miquel and Sascha,

+ Richard + linux-pm

quoted

We are having some trouble when our i.MX6 unsuspends while writes to
ubifs is in progess. In the log it looks like it syncing the filesystem
before suspend.

The SoC a i.MX6ul/ull, the issue is (lucky for us) quite easy to reproduce.
The reproduce script: [0]
Kernel log when it happens: [1]

I have bisected the bug to: ef347c0cfd61 ("mtd: rawnand: gpmi: Implement exec_op")

Any idea to where I should start looking? or to what happens?

Esben have posted to patches that relates to suspend/unsuspend but it
doesn't seem to releated to this issue.
5bc6bb603b4d ("mtd: rawnand: gpmi: Fix suspend/resume problem")
d70486668cdf ("mtd: rawnand: gpmi: Restore nfc timing setup after suspend/resume")

/Sean

nand_resume() is called some time after ubi_io_write tries to write. Thats why
mtd_write() is returning -EBUSY.

I have tried patch [3], and it seems to fix it.
I think it would be okay to add the retry option, but the mdelay is not
obviously a nogo.

Any idea to how we could wait here for the nand_resume() to be called?

@linux-pm:
I have noticed "Filsystems sync" happens before "Freezing user space
processes".
If I apply patch [4] (without [3]), it would also fix our issue. But I
don't have en insight in to what impact the change might have.

/Sean

Ping Miquel + Sascha,

Have you had time to take a look at this?

/Sean