MQX FFS Error handling in case of NANDFLASHERR_ERASE_FAILED

stefanhaase — Wed, 24 Aug 2016 13:11:44 GMT

Hello,

While investigating about the error handling capabilities of the FFS wear level layer in MQX 4.2.0.2 I stumble about an issue.

The theoretical case is as follows:

If the FFS wants to erase a block it will turn to the BSP NFC driver implementation in mqx/io/nandflash/nfc/nfc.c : nfc_erase_block() function. In case the NAND chip failed to execute successfully the Erase Block command, this function returns NANDFLASHERR_ERASE_FAILED.

I noticed that the FFS is transforming NANDFLASHERR_* codes to its own error codes in ffs/source/wearleveling/rtos/mqx/errcode.cpp : os_err_code_to_wl().

For NANDFLASHERR_ERASE_FAILED the conversion is done to ERROR_DDI_NAND_ERASE_FAILED.

I wonder why can't find any usage of this particular error code - using grep on FFS sources.

Even not on place where I would expected it!

E.g. in Mapper::getBlock() (file: ffs/source/wearleveling/ddi/mapper/mapper.cpp) :

        /* As well as setting the bit, erase physical block. */
        Block block(*pu32PhysBlkAddr);
        if (!block.isErased())
        {
            /* 
            ** If the erase fails, then loop again and try again with another block. We have
            ** already marked the bad block as used in the phy map, so we just need to mark the
            ** block itself as bad. 
            */
            rtCode = block.erase();
            if (rtCode == ERROR_DDI_NAND_HAL_WRITE_FAILED)
            {
                /* This will mark the block used in the phymap again, but not a big deal. */
                handleNewBadBlock(block);
            } /* Endif */
        } /* Endif */‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

In the above snippet at line 10 the result of the block erase command is returned and instead of checking against ERROR_DDI_NAND_ERASE_FAILED, the check is made with ERROR_DDI_NAND_HAL_WRITE_FAILED and will result in marking the block as bad.

I failed to find any path of execution that block.erase() returns ERROR_DDI_NAND_HAL_WRITE_FAILED.

So, I'm fearing about a block gets never marked as bad block by FFS.

Best Regards,

Stefan

Re: MQX FFS Error handling in case of NANDFLASHERR_ERASE_FAILED

danielchen — Fri, 26 Aug 2016 09:09:44 GMT

Hi Stefan:

I think this is an issue in FFS, block erase command returned value should be checked against ERROR_DDI_NAND_ERASE_FAILED. I will report this issue to developers.

Thank you very much for your input.

Have a nice weekend.

Regards

Daniel

topic Re: MQX FFS Error handling in case of NANDFLASHERR_ERASE_FAILED in MQX Software Solutions

MQX FFS Error handling in case of NANDFLASHERR_ERASE_FAILED

Re: MQX FFS Error handling in case of NANDFLASHERR_ERASE_FAILED