Re: GPMI iMX6ull timeout on DMA

Boris Brezillon
2019-08-09T06:24:17Z

On Fri, 9 Aug 2019 15:20:52 +1000
Greg Ungerer <gerg@kernel.org> wrote:

> Hi Boris,
>
> 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?

> Scanning device for bad blocks
> 5 ofpart partitions found on MTD device gpmi-nand
> Creating 5 MTD partitions on "gpmi-nand":
> 0x000000000000-0x000000500000 : "u-boot"
> 0x000000500000-0x000000600000 : "u-boot-env"
> 0x000000600000-0x000000800000 : "log"
> 0x000000800000-0x000010000000 : "flash"
> 0x000000000000-0x000010000000 : "all"
> gpmi-nand 1806000.gpmi-nand: driver registered.
> ...