From: Chris Ball <cjb@laptop.org>
To: elad.yi@gmail.com
Cc: linux-mmc@vger.kernel.org, Philip Rakity <prakity@nvidia.com>
Subject: Re: When bus width detection procedure takes place, kernel cannot lock on correct bus width
Date: Fri, 22 Mar 2013 13:06:45 -0400 [thread overview]
Message-ID: <87wqszl5y2.fsf@octavius.laptop.org> (raw)
In-Reply-To: <87ip4qdybr.fsf@octavius.laptop.org> (Chris Ball's message of "Sun, 17 Mar 2013 08:07:20 -0400")
Hi,
On Sun, Mar 17 2013, Chris Ball wrote:
> I've been working on a bringup of an new board in Harmonic Inc.
> This board uses Sandisk iNand eMMC flash.
> I've noticed that the mmc driver keeps detecting 1 bit width although HW
> supports 4 bit, looked into it, and found the problem. In line 571 at mmc.c:
> There is:
> /* only compare read only fields */
> err = !((card->ext_csd.raw_partition_support ==
> bw_ext_csd[EXT_CSD_PARTITION_SUPPORT]) &&
> (card->ext_csd.raw_erased_mem_count ==
> bw_ext_csd[EXT_CSD_ERASED_MEM_CONT]) &&
> (card->ext_csd.rev ==
> bw_ext_csd[EXT_CSD_REV]) &&
> (card->ext_csd.raw_ext_csd_structure ==
> ...
>
> The problem is that raw_partition_support is not the same when setting width of
> 4 bits instead of 1 bit, and shouldn't be compared at all although it is read
> only.
> this should be changed to:
> /* only compare read only fields */
> err = !((card->ext_csd.raw_erased_mem_count ==
> bw_ext_csd[EXT_CSD_ERASED_MEM_CONT]) &&
> (card->ext_csd.rev ==
> bw_ext_csd[EXT_CSD_REV]) &&
> (card->ext_csd.raw_ext_csd_structure ==
> ...
Philip, what do you think?
Thanks,
- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child
next prev parent reply other threads:[~2013-03-22 17:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-17 12:07 When bus width detection procedure takes place, kernel cannot lock on correct bus width Chris Ball
2013-03-22 17:06 ` Chris Ball [this message]
2013-03-22 18:56 ` Philip Rakity
2013-03-26 15:54 ` Philip Rakity
2013-04-04 19:37 ` Chris Ball
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