Re: GPMI iMX6ull timeout on DMA

Boris Brezillon
2019-08-08T16:37:13Z

On Mon, 5 Aug 2019 15:51:05 +1000
Greg Ungerer <gerg@kernel.org> wrote:

> Hi Boris,
>
> 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).

>
> With attached patch, I get the following dump of the timing
> settings in use:
>
> ...
> drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
> HW_GPMI_TIMING0=0x00010203 (calculated=0x00020101)
> HW_GPMI_TIMING1=0x00000000 (calculated=0x60000000)
> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00000000)
> r->clock[0]=22000000 (calculated=22000000)
> random: fast init done
> 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/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
> HW_GPMI_TIMING0=0x00010203 (calculated=0x00020101)
> HW_GPMI_TIMING1=0x00000000 (calculated=0xb0000000)
> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00000000)
> r->clock[0]=22000000 (calculated=22000000)
> drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
> HW_GPMI_TIMING0=0x00010203 (calculated=0x00010101)
> HW_GPMI_TIMING1=0x00000000 (calculated=0xe0000000)
> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00c28000)
> r->clock[0]=22000000 (calculated=100000000)
> Scanning device for bad blocks
> 5 fixed-partitions 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