我是在编译了3.0内核后发现eMMC卡怎么也初始化不了,老提示这个错误。但正常的SD卡确可以使用,经过一番研究,在结合网上查找的资料,终于将问题解决了。
在网上搜到的资料,说明了内核对eMMC4.5的支持方法:
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mmc: core: Detect eMMC v4.5 ext_csd entries
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Gitweb:
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Commit: 38ca285044be88a0fb47b6eb91deeeb729435fd0
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Parent: d5a5bd1c3f7e8d010393530d60df8da75218a488
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Author: Kyungmin Park <kyungmin.park <at> samsung.com>
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AuthorDate: Tue Jul 26 17:12:37 2011 +0900
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Committer: Chris Ball <cjb <at> laptop.org>
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CommitDate: Sat Aug 13 14:50:22 2011 -0400
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mmc: core: Detect eMMC v4.5 ext_csd entries
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The eMMC v4.5 Spec is released now:
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EXT_CSD_REV Extended CSD Revision
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255-7 Reserved
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6 Revision 1.6 (for MMC v4.5)
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5 Revision 1.5 (for MMV v4.41)
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...
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Signed-off-by: Kyungmin Park <kyungmin.park <at> samsung.com>
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Signed-off-by: Chris Ball <cjb <at> laptop.org>
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---
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drivers/mmc/core/mmc.c | 2 +-
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1 files changed, 1 insertions(+), 1 deletions(-)
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diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
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index aa7d1d7..5700b1c 100644
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--- a/drivers/mmc/core/mmc.c
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+++ b/drivers/mmc/core/mmc.c
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<at> <at> -259,7 +259,7 <at> <at> static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
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}
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card->ext_csd.rev = ext_csd[EXT_CSD_REV];
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- if (card->ext_csd.rev > 5) {
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+ if (card->ext_csd.rev > 6) {
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printk(KERN_ERR "%s: unrecognised EXT_CSD revision %d\n",
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mmc_hostname(card->host), card->ext_csd.rev);
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err = -EINVAL;
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--
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3.0的内核只支持到了eMMC-v4.41版本,对应的版本号5。
最新的eMMC-v4.5对应的版本好为6,所以程序为报错,提示版本号6不支持。只要将版本号判断修改为6即可。
eMMC-v5.0协议对EXT_CSD_REV定义:
额外的一段资料
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mmc: core: Update the ext-csd.rev check for eMMC5.1 00/55800/5
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authorYuvaraj CD <yuvaraj.cd@gmail.com>
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Tue, 21 May 2013 17:38:43 +0800 (09:38 +0000)
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committerChromeBot <chrome-bot@google.com>
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Thu, 23 May 2013 08:57:28 +0800 (17:57 -0700)
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With the new eMMC5.1 spec,there is a new EXT_CSD register with
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the revision number(EXT_CSD_REV) 7.This patch updates the check
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for ext-csd.rev number as 7.
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This patch was picked from patchwork:
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BUG=chrome-os-partner:19007
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TEST=Boot kernel on SMDK5420. /wo this patch emmc gives error "mmc0:
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unrecognised EXT_CSD revision 7"
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/w this patch the above error is not seen.
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Change-Id: I08843976eeba6e63adc27c02365f71f8d4dc6fa0
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Signed-off-by: Alim Akhtar <alim.akthar@samsung.com>
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Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
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Signed-off-by: Doug Anderson <dianders@chromium.org>
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Reviewed-on:
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drivers/mmc/core/mmc.c
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patch | blob | blame | history
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diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
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index 089e8ea..66b996f 100644 (file)
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--- a/drivers/mmc/core/mmc.c
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+++ b/drivers/mmc/core/mmc.c
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@@ -292,7 +292,7 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
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}
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card->ext_csd.rev = ext_csd[EXT_CSD_REV];
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- if (card->ext_csd.rev > 6) {
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+ if (card->ext_csd.rev > 7) {
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pr_err("%s: unrecognised EXT_CSD revision %d\n",
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mmc_hostname(card->host), card->ext_csd.rev);
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err = -EINVAL;
更是牛人,这个是在chromium.org网站有人提交的补丁,使chromiumos支持eMMC-v5.1。
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