From: Andrei Warkentin <andreiw@motorola.com>
To: Jaehoon Chung <jh80.chung@samsung.com>
Cc: linux-mmc@vger.kernel.org, cjb@laptop.org, arindam.nath@amd.com,
arnd@arndb.de, malchev@google.com,
Kyungmin Park <kyungmin.park@samsung.com>
Subject: Re: [v5 2/5] MMC: Use CMD23 for multiblock transfers when we can.
Date: Fri, 20 May 2011 13:12:07 -0500 [thread overview]
Message-ID: <BANLkTimyCO1vwjG5jnYVg+Yb=eLr6+C6hQ@mail.gmail.com> (raw)
In-Reply-To: <4DD642A0.1040608@samsung.com>
On Fri, May 20, 2011 at 5:29 AM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> Hi Andrei.
>
> I have some question..
> In mmc_blk_issue_rw_rq() of block.c, there is the below code.
>
> static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
> {
> struct mmc_blk_data *md = mq->data;
> struct mmc_card *card = md->queue.card;
> struct mmc_blk_request brq;
> int ret = 1, disable_multi = 0;
>
> /*
> * Reliable writes are used to implement Forced Unit Access and
> * REQ_META accesses, and are supported only on MMCs.
> */
> bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
> (req->cmd_flags & REQ_META)) &&
> (rq_data_dir(req) == WRITE) &&
> REL_WRITES_SUPPORTED(card);
>
> do {
> struct mmc_command cmd = {0};
> u32 readcmd, writecmd, status = 0;
>
> memset(&brq, 0, sizeof(struct mmc_blk_request));
> brq.mrq.cmd = &brq.cmd;
> brq.mrq.data = &brq.data;
>
> brq.cmd.arg = blk_rq_pos(req);
> if (!mmc_card_blockaddr(card))
> brq.cmd.arg <<= 9;
> brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> brq.data.blksz = 512;
> brq.stop.opcode = MMC_STOP_TRANSMISSION;
> brq.stop.arg = 0;
> brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
> brq.data.blocks = blk_rq_sectors(req);
>
> There is "brq.stop.opcode = MMC_STOP_TRANSMISSION".
> If we use CMD23, this line didn't need? Actually i don't know, so i ask to you.
>
Nope. Needed. CMD23 support might not be implemented by host driver
(like it isn't right now for anything non-SDHCI). And even it if were,
you still need to send stop command on any error conditions. I suggest
you read the relevant sections in the publically available eMMC spec.
A
next prev parent reply other threads:[~2011-05-20 18:12 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-14 0:38 SET_BLOCK_COUNT-bounded multiblock transfers Andrei Warkentin
2011-04-14 0:03 ` Andrei Warkentin
2011-04-14 9:05 ` Gao, Yunpeng
2011-04-14 22:58 ` Andrei Warkentin
2011-04-14 23:18 ` Chris Ball
2011-04-15 7:10 ` Andrei Warkentin
2011-04-15 17:29 ` Andrei Warkentin
2011-04-14 0:38 ` [RFC 1/3] MMC: use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-04-14 0:38 ` [RFC 2/3] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-04-14 0:38 ` [RFC 3/3] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-04-15 23:51 ` [patchv2 1/3] MMC: Use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-04-15 23:51 ` [patchv2 2/3] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-04-15 23:51 ` [patchv2 3/3] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-04-16 10:40 ` CMD23 plumbing and support patchset Andrei Warkentin
2011-04-21 1:44 ` Chris Ball
2011-04-21 6:29 ` Andrei Warkentin
2011-04-21 6:30 ` Andrei Warkentin
2011-04-22 3:53 ` Andrei Warkentin
2011-04-23 2:51 ` Chris Ball
2011-04-26 23:30 ` Andrei Warkentin
2011-04-27 2:10 ` CMD23 plumbing patchset Andrei Warkentin
2011-04-27 2:10 ` [[v4] 1/5] MMC: Add/remove quirks conditional support Andrei Warkentin
2011-04-27 2:10 ` [[v4] 2/5] MMC: Use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-04-27 2:10 ` [[v4] 3/5] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-04-27 2:10 ` [[v4] 4/5] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-04-27 2:10 ` [[v4] 5/5] MMC: SDHCI AutoCMD23 support Andrei Warkentin
2011-04-27 5:49 ` Nath, Arindam
2011-04-27 5:59 ` Andrei Warkentin
2011-04-27 6:02 ` Nath, Arindam
2011-04-27 6:05 ` Andrei Warkentin
2011-04-28 8:34 ` Nath, Arindam
2011-04-28 19:09 ` Andrei Warkentin
2011-04-29 5:34 ` Nath, Arindam
2011-05-19 2:37 ` [[v4] 2/5] MMC: Use CMD23 for multiblock transfers when we can Jaehoon Chung
2011-05-19 17:01 ` Andrei Warkentin
2011-05-20 4:38 ` Jaehoon Chung
[not found] ` <BANLkTik72KgftDWz6aNn=zGDqj1uMpwnYw@mail.gmail.com>
2011-05-20 6:54 ` Andrei Warkentin
2011-05-20 9:05 ` Jaehoon Chung
2011-05-23 12:40 ` Jaehoon Chung
2011-05-23 19:25 ` Andrei Warkentin
2011-05-23 19:33 ` Andrei Warkentin
2011-05-23 19:34 ` Andrei Warkentin
2011-05-23 20:45 ` Andrei Warkentin
2011-05-24 0:07 ` Jaehoon Chung
2011-04-29 23:25 ` CMD23 plumbing patchset Andrei Warkentin
2011-05-19 21:46 ` Andrei Warkentin
2011-05-23 20:06 ` Andrei Warkentin
2011-05-25 2:51 ` Chris Ball
2011-05-23 20:06 ` [v6 1/5] MMC: Add/remove quirks conditional support Andrei Warkentin
2011-05-23 20:06 ` [v6 2/5] MMC: Use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-05-23 20:06 ` [v6 3/5] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-05-23 20:06 ` [v6 4/5] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-05-24 6:01 ` Nath, Arindam
2011-05-23 20:06 ` [v6 5/5] MMC: SDHCI AutoCMD23 support Andrei Warkentin
2011-05-24 23:27 ` Chris Ball
2011-05-25 0:37 ` Andrei Warkentin
2011-05-19 21:46 ` [v5 1/5] MMC: Add/remove quirks conditional support Andrei Warkentin
2011-05-19 21:46 ` [v5 2/5] MMC: Use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-05-20 10:29 ` Jaehoon Chung
2011-05-20 18:12 ` Andrei Warkentin [this message]
2011-05-19 21:46 ` [v5 3/5] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-05-19 21:46 ` [v5 4/5] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-05-20 10:38 ` Nath, Arindam
2011-05-20 18:09 ` Andrei Warkentin
2011-05-19 21:46 ` [v5 5/5] MMC: SDHCI AutoCMD23 support Andrei Warkentin
2011-05-20 10:46 ` Nath, Arindam
2011-05-20 18:08 ` Andrei Warkentin
2011-04-16 10:40 ` [patchv3 1/5] MMC: Add/remove quirks conditional support Andrei Warkentin
2011-04-16 10:40 ` [patchv3 2/5] MMC: Use CMD23 for multiblock transfers when we can Andrei Warkentin
2011-04-17 17:23 ` Arnd Bergmann
2011-04-17 19:27 ` Andrei Warkentin
2011-04-19 3:44 ` Andrei Warkentin
2011-04-19 7:39 ` Arnd Bergmann
2011-04-19 15:18 ` Andrei Warkentin
2011-04-16 10:40 ` [patchv3 3/5] MMC: Implement MMC_CAP_CMD23 for SDHCI Andrei Warkentin
2011-04-16 10:40 ` [patchv3 4/5] MMC: Block CMD23 support for UHS104/SDXC cards Andrei Warkentin
2011-04-16 16:19 ` Nath, Arindam
2011-04-16 23:00 ` Andrei Warkentin
2011-04-16 23:38 ` [PATCH] " Andrei Warkentin
2011-04-16 10:40 ` [patchv3 5/5] MMC: SDHCI AutoCMD23 support Andrei Warkentin
2011-04-17 17:25 ` Arnd Bergmann
2011-04-17 19:31 ` Andrei Warkentin
2011-04-19 3:05 ` Andrei Warkentin
2011-04-19 3:19 ` Nath, Arindam
2011-04-19 3:32 ` Andrei Warkentin
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='BANLkTimyCO1vwjG5jnYVg+Yb=eLr6+C6hQ@mail.gmail.com' \
--to=andreiw@motorola.com \
--cc=arindam.nath@amd.com \
--cc=arnd@arndb.de \
--cc=cjb@laptop.org \
--cc=jh80.chung@samsung.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-mmc@vger.kernel.org \
--cc=malchev@google.com \
/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).