From: Iskren Chernev <iskren.chernev@gmail.com>
To: kernelnewbies@kernelnewbies.org
Cc: linux-mmc@vger.kernel.org
Subject: sdhci_msm issues with cold-plugged SD cards
Date: Fri, 22 May 2020 18:51:27 +0300 [thread overview]
Message-ID: <491cfef4-4a97-b6e8-0f41-d44e1c73eea4@gmail.com> (raw)
Hello,
I'm trying to add SD Card support to a smartphone (Samsung Galaxy S5). After
configuring the sdhci-msm driver through DT, it all seems to work fine except
the case when the phone boots with the SD card inserted. If the card is
re-inserted, or the driver is polling, or the probe code is forcefully executed
a second time the card is properly detected.
I logged the SD interrupts, commands and responses, and it looks like the
hardware is returning Command Index Error and/or Command End Bit Error via the
Error Interrupt Status Register, which gets converted to -EILSEQ error. On
a second attempt (due to re-insertion, polling or re-execution) these errors
are missing, and the card behaves correctly.
On the downstream kernel, these errors resulting in EILSEQ do not appear, so it
might be related to setup. Also I see that sdhci-msm driver has hardcoded
a SDHCI_QUIRK_BROKEN_CARD_DETECTION quirk, which might imply that polling
should be used (instead Card Detection GPIO), in which case this issue won't
manifest itself. But polling wastes power, and the Card Detect pin works well,
at least for this device, so I feel it can be made better.
Any suggestions on how to track this down are appreciated!
Regards,
Iskren Chernev
next reply other threads:[~2020-05-22 15:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-22 15:51 Iskren Chernev [this message]
2020-05-25 9:14 ` sdhci_msm issues with cold-plugged SD cards Ulf Hansson
2020-05-26 13:01 ` Veerabhadrarao Badiganti
2020-05-27 14:55 ` Iskren Chernev
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=491cfef4-4a97-b6e8-0f41-d44e1c73eea4@gmail.com \
--to=iskren.chernev@gmail.com \
--cc=kernelnewbies@kernelnewbies.org \
--cc=linux-mmc@vger.kernel.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;
as well as URLs for NNTP newsgroup(s).