Re: GPMI iMX6ull timeout on DMA

Boris Brezillon
2019-08-09T07:33:02Z

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?
If I'm right and you indeed dumped CTRL1, it might be worth doing the
same in your 5.1 kernel so we can more easily compare those dumps.
While at it, can you dump CTRL1 before and after applying the changes?

> 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.
>
> Regards
> Greg
>
>
> >> 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.
> >> ...
> >>