Re: GPMI iMX6ull timeout on DMA

Greg Ungerer
2019-08-05T05:52:01Z

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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?

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

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--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c 2019-03-06 15:47:24.310993476 +1000
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c 2019-08-05 15:04:49.241345883 +1000
@@ -486,6 +486,14 @@
void __iomem *gpmi_regs = r->gpmi_regs;
unsigned int dll_wait_time_us;

+#if 1
+ printk("%s(%d): gpmi_nfc_apply_timings()\n", __FILE__, __LINE__);
+ printk(" HW_GPMI_TIMING0=0x%08x (calculated=0x%08x)\n", readl(gpmi_regs + HW_GPMI_TIMING0), hw->timing0);
+ printk(" HW_GPMI_TIMING1=0x%08x (calculated=0x%08x)\n", readl(gpmi_regs + HW_GPMI_TIMING1), hw->timing1);
+ printk(" HW_GPMI_CTRL1_SET=0x%08x (calculated=0x%08x)\n", readl(gpmi_regs + HW_GPMI_CTRL1_SET), hw->ctrl1n);
+ printk(" r->clock[0]=%d (calculated=%d)\n", clk_get_rate(r->clock[0]), hw->clk_rate);
+#endif
+#if 0
clk_set_rate(r->clock[0], hw->clk_rate);

writel(hw->timing0, gpmi_regs + HW_GPMI_TIMING0);
@@ -505,6 +513,7 @@

/* Wait for the DLL to settle. */
udelay(dll_wait_time_us);
+#endif
}

int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,

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