linux-kernel - RE: [PATCH 2/2] mmc: core: Support packed command for eMMC4.5 device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5573ef5046779298ee1555838015e0e3.squirrel@www.codeaurora.org>
Date:	Thu, 1 Dec 2011 05:51:43 -0800 (PST)
From:	merez@...eaurora.org
To:	"Seungwon Jeon" <tgih.jun@...sung.com>
Cc:	merez@...eaurora.org, "'S, Venkatraman'" <svenkatr@...com>,
	linux-mmc@...r.kernel.org, "'Chris Ball'" <cjb@...top.org>,
	linux-kernel@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
	kgene.kim@...sung.com, dh.han@...sung.com
Subject: RE: [PATCH 2/2] mmc: core: Support packed command for eMMC4.5 
     device

> Maya Erez wrote:
>> >> >> On Wed, Nov 2, 2011 at 1:33 PM, Seungwon Jeon
>> <tgih.jun@...sung.com>
>> >> wrote:
>> >> >> > @@ -980,12 +988,67 @@ static int mmc_blk_err_check(struct
>> mmc_card
>> >> *card,
>> >> >> >        if (!brq->data.bytes_xfered)
>> >> >> >                return MMC_BLK_RETRY;
>> >> >> >
>> >> >> > +       if (mq_mrq->packed_cmd != MMC_PACKED_NONE) {
>> >> >> > +               if (unlikely(brq->data.blocks << 9 !=
>> >> brq->data.bytes_xfered))
>> >> >> > +                       return MMC_BLK_PARTIAL;
>> >> >> > +               else
>> >> >> > +                       return MMC_BLK_SUCCESS;
>> >> >> > +       }
>> >> >> > +
>> >> >> >        if (blk_rq_bytes(req) != brq->data.bytes_xfered)
>> >> >> >                return MMC_BLK_PARTIAL;
>> >> >> >
>> >> >> >        return MMC_BLK_SUCCESS;
>> >> >> >  }
>> >> >> >
>> >> >> > +static int mmc_blk_packed_err_check(struct mmc_card *card, +
>>                        struct mmc_async_req *areq)
>> >> >> > +{
>> >> >> > +       struct mmc_queue_req *mq_mrq = container_of(areq, struct
>> >> mmc_queue_req,
>> >> >> > +                                                   mmc_active);
>> +
>>       int err, check, status;
>> >> >> > +       u8 ext_csd[512];
>> >> >> > +
>> >> >> > +       check = mmc_blk_err_check(card, areq);
>> >> >> > +
>> >> >> > +       if (check == MMC_BLK_SUCCESS)
>> >> >> > +               return check;
>> I think we need to check the status for all cases and not only in case
>> of
>> MMC_BLK_PARTIAL. For example, in cases where the header was traferred
>> successfully but had logic errors (wrong number of sectors etc.)
>> mmc_blk_err_check will return MMC_BLK_SUCCESS although the packed
>> commands
>> failed.
> Similarly, Sahitya Tummala is already mentioned this.
> Other error case will be checked in next version.
> The case you suggested is about read or write?
> Device may detect error and stop transferring the data.
Sahitya suggested to also check other error cases that mmc_blk_err_check
returns (such as MMC_BLK_CMD_ERR, MMC_BLK_ECC_ERR and MMC_BLK_DATA_ERR).
I suggest to also check the exception bit in the status even if
mmc_blk_err_check returned success, since mmc_blk_err_check might not
catch all the packed commands failures. One example for such a failure is
when the header of read packed commands will have logical error.

Thanks,
Maya
--
Seny by a Consultant for Qualcomm innovation center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/