From: Markus Niebel <list-09_u-boot@tqsc.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] MMC and buffer alignment question
Date: Wed, 19 Mar 2014 15:16:29 +0100 [thread overview]
Message-ID: <5329A6BD.3090309@tqsc.de> (raw)
Hello Pantelis,
short question to the usage of the mmc command (and also the mmc driver API): is it intended that mmc read / write may fail when the supplied address in RAM is not aligned?
ARMV7 will give output like this:
U-Boot > mmc read 12000002 44 44
MMC read: dev # 0, block # 68, count 68 ... INFO: 24994 of 25000 loops left to DAT0 timeout
ERROR: v7_dcache_inval_range - start address is not aligned - 0x12000002
ERROR: v7_dcache_inval_range - stop address is not aligned - 0x12008802
68 blocks read: OK
On my platform (i.MX6 / Cortex A9) the alignment needed is 32 Byte.
Special commands inside the mmc drivers and in env_mmc implement the alignment magic. Shouldn't the mmc do the magic (and if neccesarry provide help using temp buffers if needed) so that all users outside can read / write without caring for special cases?
Markus
next reply other threads:[~2014-03-19 14:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-19 14:16 Markus Niebel [this message]
2014-03-19 14:22 ` [U-Boot] MMC and buffer alignment question Eric Nelson
2014-03-19 14:44 ` Wolfgang Denk
2014-03-19 17:40 ` Markus Niebel
2014-03-19 18:18 ` Eric Nelson
2014-03-19 19:17 ` Wolfgang Denk
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5329A6BD.3090309@tqsc.de \
--to=list-09_u-boot@tqsc.de \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.