Re: GPMI iMX6ull timeout on DMA

Boris Brezillon
2019-08-09T13:59:58Z

On Fri, 9 Aug 2019 23:57:08 +1000
Greg Ungerer <gerg@kernel.org> wrote:

> Hi Boris,
>
> On 9/8/19 5:32 pm, Boris Brezillon wrote:
> > On Fri, 9 Aug 2019 16:55:22 +1000
> > Greg Ungerer <gerg@kernel.org> wrote:
> >> On 9/8/19 4:23 pm, Boris Brezillon wrote:
> >>> On Fri, 9 Aug 2019 15:20:52 +1000
> >>> Greg Ungerer <gerg@kernel.org> wrote:
> >>>> On 9/8/19 2:36 am, Boris Brezillon wrote:
> >>>>> On Mon, 5 Aug 2019 15:51:05 +1000
> >>>>> Greg Ungerer <gerg@kernel.org> wrote:
> >>>>>> On 2/8/19 10:51 pm, Boris Brezillon wrote:
> >>>>>>> On Fri, 2 Aug 2019 22:34:57 +1000
> >>>>>>> Greg Ungerer <gerg@kernel.org> wrote:
> >>>>>>>> On 31/7/19 4:28 pm, Boris Brezillon wrote:
> >>>>>>>>> On Wed, 31 Jul 2019 12:05:44 +1000
> >>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote:
> >>>>>>>>>> On 30/7/19 6:38 pm, Miquel Raynal wrote:
> >>>>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Tue, 30 Jul 2019 16:06:55 +1000:
> >>>>>>>>>>>> On 30/7/19 10:41 am, Greg Ungerer wrote:
> >>>>>>>>>>>>> On 30/7/19 10:28 am, Greg Ungerer wrote:
> >>>>>>>>>>>>>> On 29/7/19 10:47 pm, Miquel Raynal wrote:
> >>>>>>>>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Mon, 29 Jul 2019 22:33:56 +1000:
> >>>>>>>>>>>>>>>> On 29/7/19 6:36 pm, Miquel Raynal wrote:
> >>>>>>>>>>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Mon, 29 Jul 2019 16:41:51 +1000:
> >>>>>>>>>>>>> [snip]
> >>>>>>>>>> Note that this was generated on a normal boot up (not failure).
> >>>>>>>>>
> >>>>>>>>> The values looks good. Can you try with the below diff applied?
> >>>>>>>>> --->8---
> >>>>>>>>> diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> >>>>>>>>> index 334fe3130285..9771f6a82abe 100644
> >>>>>>>>> --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> >>>>>>>>> +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> >>>>>>>>> @@ -721,12 +721,10 @@ static void gpmi_nfc_apply_timings(struct gpmi_nand_data *this)
> >>>>>>>>> writel(hw->ctrl1n, gpmi_regs + HW_GPMI_CTRL1_SET);
> >>>>>>>>>
> >>>>>>>>> /* Wait 64 clock cycles before using the GPMI after enabling the DLL */
> >>>>>>>>> - dll_wait_time_us = USEC_PER_SEC / hw->clk_rate * 64;
> >>>>>>>>> - if (!dll_wait_time_us)
> >>>>>>>>> - dll_wait_time_us = 1;
> >>>>>>>>> + dll_wait_time_us = DIV_ROUND_UP(USEC_PER_SEC * 64, hw->clk_rate);
> >>>>>>>>>
> >>>>>>>>> /* Wait for the DLL to settle. */
> >>>>>>>>> - udelay(dll_wait_time_us);
> >>>>>>>>> + usleep_range(dll_wait_time_us, dll_wait_time_us * 10);
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> static int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,
> >>>>>>>>
> >>>>>>>> Eventually it failed, in the same way with with same errors.
> >>>>>>>> Took quite a while, over 600 boot cycles.
> >>>>>>>>
> >>>>>>>> Note also that I had to hand merge the changes, since in 5.1.14 that
> >>>>>>>> gpmi_nfc_apply_timings() is in gpmi-lib.c. But it was trivial to do.
> >>>>>>>
> >>>>>>> Oh well. I guess the next thing to do would be to dump the timing regs
> >>>>>>> and clk rate that are set by the bootloader (before the driver override
> >>>>>>> them) or those applied by an older kernel (one that didn't have that
> >>>>>>> issue).
> >>>>>>
> >>>>>> Is this useful?
> >>>>>
> >>>>> Hm, looks like it's configured in mode 0, so no, it's not super useful.
> >>>>> Can you try booting an older kernel (one that didn't have the
> >>>>> ->setup_data_interface() hook implemented).
> >>>>
> >>>> Ok. I went back from 5.1 and the first kernel I could find that
> >>>> returned no grep hits for "setup_data_interface" was 4.16.
> >>>>
> >>>> So I built for my target with that and added similar trace to dump
> >>>> the hardware register settings for that. Debug output looks like
> >>>> this now for it:
> >>>>
> >>>> ...
> >>>> drivers/mtd/nand/gpmi-nand/gpmi-nand.c(807): gpmi_get_clks()
> >>>> clk_get_rate(r->clock[0])=22000000
> >>>> drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
> >>>> HW_GPMI_TIMING0=0x00010203
> >>>> HW_GPMI_TIMING1=0x05000000
> >>>> nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
> >>>> nand: Micron MT29F2G08ABAEAWP
> >>>> nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
> >>>> drivers/mtd/nand/gpmi-nand/gpmi-lib.c(966): enable_edo_mode()
> >>>> clk_get_rate(r->clock[0])=99000000
> >>>> gpmi-nand 1806000.gpmi-nand: enable the asynchronous EDO mode 5
> >>>> drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
> >>>> HW_GPMI_TIMING0=0x00010101
> >>>
> >>> TIMING0 match the one you have with 5.1 kernels.
> >>>
> >>>> HW_GPMI_TIMING1=0x90000000
> >>>
> >>> And we even have a bigger timeout value in 5.1 (0xe0000000), so we
> >>> should be all safe WRT to timings in TIMING{0,1}.
> >>>
> >>> Can you dump CTRL1?
> >>
> >> drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
> >> HW_GPMI_TIMING0=0x00010101
> >> HW_GPMI_TIMING1=0x90000000
> >> HW_GPMI_CTRL1_SET=0x01c4800c
> >
> > The read/write delay fields seem to match, but there are a few more
> > fields set in this version:
> > - DECOUPLE_CS
> > - BCH_MODE
> > - DEV_RESET
> > - CTRL1_ATA_IRQRDY_POLARITY__ACTIVEHIGH
> >
> > Looks like those fields are not explicitly set in the gpmi_begin()
> > patch, but maybe you dumped CTRL1. Would you mind sharing your patch?
>
> Attached.

Hm, you should read CTRL1 instead of CTRL1_SET which I guess is WO.