Re: [PATCH v2] mtd: rawnand: Increment IFC_TIMEOUT_MSECS for nand controller response

[Ronald Monthero]

Hi Andy,
Thanks for the feedback, I had not seen your response by then. I will
modify and send it again.

BR,
Ron

On Tue, Nov 14, 2023 at 2:04 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> You are too quick with v2, below my comments (new and old).
>
> On Tue, Nov 14, 2023 at 01:53:51AM +1000, Ronald Monthero wrote:
> > Under heavy load it is likely that the controller is done
> > with its own task but the thread unlocking the wait is not
> > scheduled in time. Increasing IFC_TIMEOUT_MSECS allows the
> > controller to respond within allowable timeslice of 1 sec
>
> Missing period at the end?
>
> > fsl,ifc-nand 7e800000.nand: Controller is not responding
>
> > main/smp_fsm.c:1884 <inrcu: rcu_preempt detected stalls on CPUs/tasks:
> > rcu:    Tasks blocked on level-0 rcu_node (CPUs 0-1): P116/2:b..l
> >         (detected by 1, t=2102 jiffies, g=7729, q=754)
> > task:irq/31-arm-irq1 state:D stack: 0 pid: 116 ppid: 2 flags:0x00000000
> > [<8064b97f>] (__schedule) from [<8064bb01>] (schedule+0x8d/0xc2)
> > [<8064bb01>] (schedule) from [<8064dacd>]
> > [<8064dacd>] (rt_mutex_slowlock_block.constprop.0) from [<8064db57>]
> > [<8064db57>] (__rt_mutex_slowlock.constprop.0) from [<8064dbf7>]
> > [<8064dbf7>] (rt_mutex_slowlock.constprop.0) from [<804b2047>]
>
> At least above 9 lines are not important and may be removed.
>
> > [<804b2047>] (nand_get_device) from [<804b5335>] (nand_write_oob+0x1b/0x4a)
> > [<804b5335>] (nand_write_oob) from [<804a3585>] (mtd_write+0x41/0x5c)
> > [<804a3585>] (mtd_write) from [<804c1d47>] (ubi_io_write+0x17f/0x22c)
> > [<804c1d47>] (ubi_io_write) from [<804c047b>] (ubi_eba_write_leb+0x5b/0x1d0)
>
> ...
>
> > -#define IFC_TIMEOUT_MSECS    500  /* Maximum number of mSecs to wait
> > +#define IFC_TIMEOUT_MSECS    1000  /* Maximum number of mSecs to wait
> >                                       for IFC NAND Machine    */
>
> While at it, you may improve the comment, e.g.,
>
>   "Maximum timeout to wait for IPC NAND Machine"
>
> --
> With Best Regards,
> Andy Shevchenko
>
>