All of lore.kernel.org
 help / color / mirror / Atom feed
* SET_BLOCK_COUNT-bounded multiblock transfers
@ 2011-04-14  0:38 Andrei Warkentin
  2011-04-14  0:03 ` Andrei Warkentin
                   ` (12 more replies)
  0 siblings, 13 replies; 85+ messages in thread
From: Andrei Warkentin @ 2011-04-14  0:38 UTC (permalink / raw)
  To: linux-mmc; +Cc: arnd, cjb

This is a request for comments for a patch set that enables
predefined multiblock transfers if these are supported.

Before this patch set, all multiblock transfers look like (for example)

CMD25 -> [block] [block] [block] [block] -> CMD12 (stop)

...or for controllers with Auto-CMD12

CMD25 -> [block] [block] [block] [block] (host sends CMD12 itself).

We want to enable - 

CMD23(4 blocks) CMD25 [data] [data] [data] [data]

...and for controllers with Auto-CMD23 -

(Host sends CMD23(4 blocks)) CMD25 [data] [data] [data] [data]

The interrupt overhead is the same, but for cards that optimize for predefined transfers
we can see better transfer rates. I've tested this on a Sandisk eMMC where I saw as good as
a 50% improvement on writes, and on a Toshiba eMMC where I saw no improvement at all. Also,
reliable writes use CMD23, so this cleans up that code path as well. Note, that if a transfer
fails, CMD12 must still be sent, so it is not sufficient to just not fill the mrq->stop field
while doing a CMD23-enabled transfer. Due to this error handling and off-loads of Auto-CMD23
(and interaction with Auto-CMD12) handling of SET_BLOCK_COUNT, just like STOP, is left to the host driver.
Host driver now exposes MMC_CAP_CMD23 if it has been changed to handle the new "sbc" field in struct mmc_request.
If a host doesn't expose this capability, open-ended transfers are used, and all functionality
relying on CMD23 (such as reliable writes) is disabled.

The third patch has been only tested on SD cards that don't expose CMD23. Still need to get an SDXC
card and test it out, but I wanted to get eyes on this patch set anyway :-).

I had a fourth patch enabling Auto-CMD23 for SDHCI, but I'll hold off until I can verify it.

Thoughts?

Table of Contents:
[RFC 1/3] MMC: use CMD23 for multiblock transfers when we can.
[RFC 2/3] MMC: Implement MMC_CAP_CMD23 for SDHCI.
[RFC 3/3] MMC: Block CMD23 support for UHS104/SDXC cards.

A

^ permalink raw reply	[flat|nested] 85+ messages in thread

end of thread, other threads:[~2011-05-25  2:49 UTC | newest]

Thread overview: 85+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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
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

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.