linux.git/include/linux/mmc, branch v4.14-rc4

mmc: Delete bounce buffer handling

2017-10-04T08:22:55+00:00

In may, Steven sent a patch deleting the bounce buffer handling
and the CONFIG_MMC_BLOCK_BOUNCE option.

I chose the less invasive path of making it a runtime config
option, and we merged that successfully for kernel v4.12.

The code is however just standing in the way and taking up
space for seemingly no gain on any systems in wide use today.

Pierre says the code was there to improve speed on TI SDHCI
controllers on certain HP laptops and possibly some Ricoh
controllers as well. Early SDHCI controllers lacked the
scatter-gather feature, which made software bounce buffers
a significant speed boost.

We are clearly talking about the list of SDHCI PCI-based
MMC/SD card readers found in the pci_ids[] list in
drivers/mmc/host/sdhci-pci-core.c.

The TI SDHCI derivative is not supported by the upstream
kernel. This leaves the Ricoh.

What we can however notice is that the x86 defconfigs in the
kernel did not enable CONFIG_MMC_BLOCK_BOUNCE option, which
means that any such laptop would have to have a custom
configured kernel to actually take advantage of this
bounce buffer speed-up. It simply seems like there was
a speed optimization for the Ricoh controllers that noone
was using. (I have not checked the distro defconfigs but
I am pretty sure the situation is the same there.)

Bounce buffers increased performance on the OMAP HSMMC
at one point, and was part of the original submission in
commit a45c6cb81647 ("[ARM] 5369/1: omap mmc: Add new
   omap hsmmc controller for 2430 and 34xx, v3")

This optimization was removed in
commit 0ccd76d4c236 ("omap_hsmmc: Implement scatter-gather
   emulation")
which found that scatter-gather emulation provided even
better performance.

The same was introduced for SDHCI in
commit 2134a922c6e7 ("sdhci: scatter-gather (ADMA) support")

I am pretty positively convinced that software
scatter-gather emulation will do for any host controller what
the bounce buffers were doing. Essentially, the bounce buffer
was a reimplementation of software scatter-gather-emulation in
the MMC subsystem, and it should be done away with.

Cc: Pierre Ossman 
Cc: Juha Yrjola 
Cc: Steven J. Hill 
Cc: Shawn Lin 
Cc: Adrian Hunter 
Suggested-by: Steven J. Hill 
Suggested-by: Shawn Lin 
Signed-off-by: Linus Walleij 
Signed-off-by: Ulf Hansson

Merge tag 'mmc-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

2017-09-07T19:24:50+00:00

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Continue to refactor the mmc block code to prepare for blkmq
   - Move mmc block debugfs into block module
   - Next step for eMMC CMDQ by adding a new mmc host interface for it
   - Move Kconfig option MMC_DEBUG from core to host
   - Some additional minor improvements

  MMC host:
   - Declare structs as const when applicable
   - Explicitly request exclusive reset control when applicable
   - Improve some error paths and other various cleanups
   - sdhci: Preparations to support SDHCI OMAP
   - sdhci: Improve some PM related code
   - sdhci: Re-factoring and modernizations
   - sdhci-xenon: Add runtime PM and system sleep support
   - sdhci-xenon: Add support for eMMC HS400 Enhanced Strobe
   - sdhci-cadence: Add system sleep support
   - sdhci-of-at91: Improve system sleep support
   - dw_mmc: Add support for Hisilicon hi3660
   - sunxi: Add support for A83T eMMC
   - sunxi: Add support for DDR52 mode
   - meson-gx: Add support for UHS-I SD-cards
   - meson-gx: Cleanups and improvements
   - tmio: Fix CMD12 (STOP) handling
   - tmio: Cleanups and improvements
   - renesas_sdhi: Add r8a7743/5 support
   - renesas-sdhi: Add support for R-Car Gen3 SDHI DMAC
   - renesas_sdhi: Cleanups and improvements"

* tag 'mmc-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (145 commits)
  mmc: renesas_sdhi: Add r8a7743/5 support
  mmc: meson-gx: fix __ffsdi2 undefined on arm32
  mmc: sdhci-xenon: add runtime pm support and reimplement standby
  mmc: core: Move mmc_start_areq() declaration
  mmc: mmci: stop building qcom dml as module
  mmc: sunxi: Reset the device at probe time
  clk: sunxi-ng: Provide a default reset hook
  mmc: meson-gx: rework tuning function
  mmc: meson-gx: change default tx phase
  mmc: meson-gx: implement voltage switch callback
  mmc: meson-gx: use CCF to handle the clock phases
  mmc: meson-gx: implement card_busy callback
  mmc: meson-gx: simplify interrupt handler
  mmc: meson-gx: work around clk-stop issue
  mmc: meson-gx: fix dual data rate mode frequencies
  mmc: meson-gx: rework clock init function
  mmc: meson-gx: rework clk_set function
  mmc: meson-gx: rework set_ios function
  mmc: meson-gx: cfg init overwrite values
  mmc: meson-gx: initialize sane clk default before clock register
  ...

mmc: core: Move mmc_start_areq() declaration

2017-08-30T13:03:53+00:00

mmc_start_areq() is an internal mmc core API. Move the declaration
accordingly.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: host: Add CQE interface

2017-08-30T13:03:33+00:00

Add CQE host operations, capabilities, and host members.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: core: Add members to mmc_request and mmc_data for CQE's

2017-08-30T12:02:01+00:00

Most of the information needed to issue requests to a CQE is already in
struct mmc_request and struct mmc_data. Add data block address, some flags,
and the task id (tag), and allow for cmd being NULL which it is for CQE
tasks.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson

mmc: core: Remove unused MMC_CAP2_PACKED_CMD

2017-08-30T12:02:00+00:00

Packed commands support was removed but some bits got left behind. Remove
them.

Signed-off-by: Adrian Hunter 
Reviewed-by: Linus Walleij 
Signed-off-by: Ulf Hansson

mmc: core: correct taac parameter according to the specification

2017-08-30T12:01:46+00:00

Per the spec of JESD84-B51, section 7.3, replace tacc with taac to
fix the obvious typo.

Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson

mmc: core: remove check of host->removed for rescan routine

2017-08-30T12:01:33+00:00

The intention of this check was to prevent the conflict between
hotplug and removing driver for whatever reason. Currently it
doesn't improve anything and the following rescan process could
still saftly perform the scan flow. So these code seems pointless
now and let's remove them.

Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson

brcmfmac: Add support for CYW4373 SDIO/USB chipset

2017-08-08T11:51:12+00:00

Add support for CYW4373 SDIO/USB chipset.
CYW4373 is a 1x1 dual-band 11ac chipset with 20/40/80Mhz channel support.
It's a WiFi/BT combo device.

Signed-off-by: Chi-Hsien Lin 
Reviewed-by: Arend van Spriel 
Signed-off-by: Kalle Valo

mmc: slot-gpio: Add support to enable irq wake on cd_irq

2017-06-20T08:30:49+00:00

Add host capability MMC_CAP_CD_WAKE to enable irq wake on the card detect
irq.

Signed-off-by: Adrian Hunter 
Signed-off-by: Ulf Hansson