From: Jules Maselbas <jmaselbas@zdiv.net>
To: barebox@lists.infradead.org
Cc: Jules Maselbas <jmaselbas@zdiv.net>
Subject: [PATCH] mci: core: clarify comment on MMC version detection
Date: Thu, 13 Jun 2024 15:53:38 +0200 [thread overview]
Message-ID: <20240613135338.21202-1-jmaselbas@zdiv.net> (raw)
The MMC version is read from the reserved bits 125:122 in the CSD register,
theses bits are specified as SPEC_VERS by JEDEC in the eMMC standard JESD84.
Signed-off-by: Jules Maselbas <jmaselbas@zdiv.net>
---
drivers/mci/mci-core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index de1efe3bb9..5a8f81ecb8 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -936,15 +936,15 @@ static void mci_set_bus_width(struct mci *mci, enum mci_bus_width width)
/**
* Extract card's version from its CSD
* @param mci MCI instance
- * @return 0 on success
*/
static void mci_detect_version_from_csd(struct mci *mci)
{
int version;
if (mci->version == MMC_VERSION_UNKNOWN) {
- /* the version is coded in the bits 127:126 (left aligned) */
- version = (mci->csd[0] >> 26) & 0xf; /* FIXME why other width? */
+ /* this should only apply to MMC card, JESD84-B51 defines
+ * bits 125:122 as SPEC_VER (reserved bits in CSD) */
+ version = (mci->csd[0] >> 26) & 0xf;
switch (version) {
case 0:
--
2.45.0
next reply other threads:[~2024-06-13 13:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-13 13:53 Jules Maselbas [this message]
2024-06-14 6:33 ` Sascha Hauer
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=20240613135338.21202-1-jmaselbas@zdiv.net \
--to=jmaselbas@zdiv.net \
--cc=barebox@lists.infradead.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox