U-Boot OMAP GPMC ECC change
Roger Quadros
rogerq at kernel.org
Wed May 17 15:30:55 CEST 2023
Hi Colin,
On 12/05/2023 19:05, Colin Foster wrote:
> Hi Roger,
>
> On Fri, May 12, 2023 at 02:53:07PM +0300, Roger Quadros wrote:
>>
>>
>> On 10/05/2023 18:38, Colin Foster wrote:
>>>
>>> This is still out-of-U-Boot. I have an include/configs/our_product.h
>>> file with this:
>>>
>>> """
>>> #define CFG_SYS_NAND_ECCPOS {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, \
>>> 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, \
>>> 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, \
>>> 33, 34, 35, 36, 37, 38, 39, 40, 41, \
>>> 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, \
>>> 52, 53, 54, 55, 56, 57}
>>>
>>> #define CFG_SYS_NAND_ECCBYTES 14
>>> #define CFG_SYS_NAND_MAX_ECCPOS 57
>>
>> This should be 56 i.e. (57 - 2 + 1)
>> But it won't fix the issue you are facing. :P
>
> Oh, good catch. I know when I was trying to get this working I had to
> play with these values quite a bit. I must have missed changing this at
> one point.
>
>>
>>> #define CFG_SYS_NAND_ECCSIZE 512
>>> #define CFG_SYS_NAND_MAX_OOBFREE 2
>>> """
>>>
>>>
>>>> Can you please point me to the Linux device tree file if it exists?
>>>
>>> This is the latest submission. Still not accepted - I need to find time
>>> to button everything up and resubmit. My plan of attack was Kernel
>>> Acceptance, then U-Boot. Unfortunately my company lets the pesky
>>> "Shipping products" step get in the way :-)
>>>
>>> https://lkml.org/lkml/2023/2/22/939
>>>
>>> Or if you just want the ECC part:
>>>
>>> + nandflash: nand at 0,0 {
>>> + compatible = "ti,omap2-nand";
>>> + reg = <0 0 4>;
>>> + interrupt-parent = <&gpmc>;
>>> +
>>> + nand-bus-width = <16>;
>>> + ti,nand-ecc-opt = "bch8";
>>> + ti,elm-id=<&elm>;
>>> + linux,mtd-name = "micron,nand";
>>>
>>>
>>> I think that's all the info you're looking for. Let me know if I missed
>>> something.
>>
>> Yes this is all I was looking for.
>>
>> Is CONFIG_NAND_OMAP_ECCSCHEME_BCH8_CODE_HW set in your u-boot config?
>
> Yes, it is set. I've attached our .config file. I just made a change to
> CONFIG_NAND_OMAP_GPMC_PREFETCH as a test, which didn't fix the issue.
>
> And as another sanity check, I reverted the patch and have functionality
> again:
>
I just tested this on AM335x EVM which uses BCH8_CODE_HW but 8-bit NAND part.
I see that you are using 16-bit NAND.
One more difference in u-boot configuration. For me:
CONFIG_NAND_OMAP_GPMC_PREFETCH=y
Not sure if that matters but let's keep it set for now.
For debug can you please apply the patch (at end) to u-boot at commit a95410696d21
(before breakage) and run the test.
Test procedure:
> nand dump 0
> mmc dev 0
#replace 0 with whatever points to SD-card
> nand read $loadaddr 0 800
#loadaddr is any address in RAM which is free for use.
> fatwrite mmc 0:1 $loadaddr nand.org 800
- restore NAND page 0
> fatload mmc 0:1 $loadaddr nand.org
> nand write $loadaddr 0 800
Now please run the below test on the offending commit 04fcd25873 after applying
the patch (at end).
> nand dump 0
> mmc dev 0
#replace 0 with whatever points to SD-card
> fatload mmc 0:1 $loadaddr nand.org
> nand write $loadaddr 0 800
Please send me the logs of both tests and the nand.org file so I can try it out here. Thanks!
--- patch starts---
diff --git a/drivers/mtd/nand/raw/omap_gpmc.c b/drivers/mtd/nand/raw/omap_gpmc.c
index be3cb3c601..ac06d5f019 100644
--- a/drivers/mtd/nand/raw/omap_gpmc.c
+++ b/drivers/mtd/nand/raw/omap_gpmc.c
@@ -300,6 +300,7 @@ static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
ecc_code[i++] = (val >> 0) & 0xFF;
ptr--;
}
+ printf("ecc: %x\n", val);
break;
case OMAP_ECC_BCH16_CODE_HW:
val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[2]);
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