<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/mmc/core, branch v3.10.28</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'mmc-updates-for-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc</title>
<updated>2013-05-04T20:45:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-05-04T20:45:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=173192958d06b8d1eb44f56d74373052ad6a9a60'/>
<id>173192958d06b8d1eb44f56d74373052ad6a9a60</id>
<content type='text'>
Pull MMC update from Chris Ball:
 "MMC highlights for 3.10:

  Core:
   - Introduce MMC_CAP2_NO_PRESCAN_POWERUP to allow skipping
     mmc_power_up() at boot/initialization time if it's already
     happened, for performance (faster boot time) reasons.
   - Fix a bit width test failure that resulted in old eMMC cards being
     put into 1-bit mode when 4-bit mode was available.
   - Expose fwrev/hwrev for MMCv4 parts.
   - Improve card removal logic in the case where the card's removed
     slowly; we were missing card removal events if the card retained
     contact with the slot pads for long enough to reply to a CMD13
     while being removed.

  Drivers:
   - davinci_mmc: Support using PIO instead of DMA.
   - dw_mmc: Add support for Exynos4412.
   - mxcmmc: DT support, use slot-gpio API.
   - mxs-mmc: Add broken-cd/cd-inverted/non-removable DT property
     support.
   - sdhci-sirf: New sdhci-pltfm driver for CSR SiRF SoCs:
       SiRFprimaII: unicore ARM Cortex-A9
       SiRFatlas6: unicore ARM Cortex-A9
       SiRFmarco: dual core ARM Cortex-A9 SMP
   - sdhci-tegra: Add support for Tegra114 platforms, use
     mmc_of_parse()"

* tag 'mmc-updates-for-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (66 commits)
  mmc: sdhci-tegra: fix MODULE_DEVICE_TABLE
  mmc: core: fix init controller performance regression, updated patch
  mmc: mxcmmc: enable DMA support on mpc512x
  mmc: mxcmmc: constify mxcmci_devtype
  mmc: mxcmmc: use slot-gpio API for write-protect detection
  mmc: mxcmmc: add mpc512x SDHC support
  mmc: mxcmmc: fix race conditions for host-&gt;req and host-&gt;data access
  mmc: mxcmmc: DT support
  mmc: dw_mmc: let device core setup the default pin configuration
  mmc: mxs-mmc: add broken-cd property
  mmc: mxs-mmc: add non-removable property
  mmc: mxs-mmc: add cd-inverted property
  mmc: core: call pm_runtime_put_noidle in pm_runtime_get_sync failed case
  mmc: mxcmmc: Fix bug when card is present during boot
  mmc: core: fix performance regression initializing MMC host controllers
  Revert "mmc: core: wait while adding MMC host to ensure root mounts successfully"
  mmc: atmel-mci: pio hang on block errors
  mmc: core: Fix bit width test failing on old eMMC cards
  mmc: dw_mmc: Use pr_info instead of printk
  mmc: dw_mmc: Check return value of regulator_enable
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MMC update from Chris Ball:
 "MMC highlights for 3.10:

  Core:
   - Introduce MMC_CAP2_NO_PRESCAN_POWERUP to allow skipping
     mmc_power_up() at boot/initialization time if it's already
     happened, for performance (faster boot time) reasons.
   - Fix a bit width test failure that resulted in old eMMC cards being
     put into 1-bit mode when 4-bit mode was available.
   - Expose fwrev/hwrev for MMCv4 parts.
   - Improve card removal logic in the case where the card's removed
     slowly; we were missing card removal events if the card retained
     contact with the slot pads for long enough to reply to a CMD13
     while being removed.

  Drivers:
   - davinci_mmc: Support using PIO instead of DMA.
   - dw_mmc: Add support for Exynos4412.
   - mxcmmc: DT support, use slot-gpio API.
   - mxs-mmc: Add broken-cd/cd-inverted/non-removable DT property
     support.
   - sdhci-sirf: New sdhci-pltfm driver for CSR SiRF SoCs:
       SiRFprimaII: unicore ARM Cortex-A9
       SiRFatlas6: unicore ARM Cortex-A9
       SiRFmarco: dual core ARM Cortex-A9 SMP
   - sdhci-tegra: Add support for Tegra114 platforms, use
     mmc_of_parse()"

* tag 'mmc-updates-for-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (66 commits)
  mmc: sdhci-tegra: fix MODULE_DEVICE_TABLE
  mmc: core: fix init controller performance regression, updated patch
  mmc: mxcmmc: enable DMA support on mpc512x
  mmc: mxcmmc: constify mxcmci_devtype
  mmc: mxcmmc: use slot-gpio API for write-protect detection
  mmc: mxcmmc: add mpc512x SDHC support
  mmc: mxcmmc: fix race conditions for host-&gt;req and host-&gt;data access
  mmc: mxcmmc: DT support
  mmc: dw_mmc: let device core setup the default pin configuration
  mmc: mxs-mmc: add broken-cd property
  mmc: mxs-mmc: add non-removable property
  mmc: mxs-mmc: add cd-inverted property
  mmc: core: call pm_runtime_put_noidle in pm_runtime_get_sync failed case
  mmc: mxcmmc: Fix bug when card is present during boot
  mmc: core: fix performance regression initializing MMC host controllers
  Revert "mmc: core: wait while adding MMC host to ensure root mounts successfully"
  mmc: atmel-mci: pio hang on block errors
  mmc: core: Fix bit width test failing on old eMMC cards
  mmc: dw_mmc: Use pr_info instead of printk
  mmc: dw_mmc: Check return value of regulator_enable
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: rename random32() to prandom_u32()</title>
<updated>2013-04-30T01:28:42+00:00</updated>
<author>
<name>Akinobu Mita</name>
<email>akinobu.mita@gmail.com</email>
</author>
<published>2013-04-29T23:21:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e744fcb90599819b43415e2e6d6a6a550248645'/>
<id>2e744fcb90599819b43415e2e6d6a6a550248645</id>
<content type='text'>
Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Cc: Chris Ball &lt;cjb@laptop.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Cc: Chris Ball &lt;cjb@laptop.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: fix init controller performance regression, updated patch</title>
<updated>2013-04-15T15:27:25+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-04-15T15:27:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a08b17be8b984a7c51cd5a480cd977363df353f9'/>
<id>a08b17be8b984a7c51cd5a480cd977363df353f9</id>
<content type='text'>
Add MMC_CAP2_NO_PRESCAN_POWERUP to sdhci-pci.c also, use mmc_power_off()
for MMC_CAP2_NO_PRESCAN_POWERUP.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
[cjb: previously applied v1 of this patch instead of v4]
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add MMC_CAP2_NO_PRESCAN_POWERUP to sdhci-pci.c also, use mmc_power_off()
for MMC_CAP2_NO_PRESCAN_POWERUP.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
[cjb: previously applied v1 of this patch instead of v4]
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: call pm_runtime_put_noidle in pm_runtime_get_sync failed case</title>
<updated>2013-04-12T18:15:04+00:00</updated>
<author>
<name>Li Fei</name>
<email>fei.li@intel.com</email>
</author>
<published>2013-04-08T01:36:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3bffb800b91bb128b61d83deb01ce63c455d108f'/>
<id>3bffb800b91bb128b61d83deb01ce63c455d108f</id>
<content type='text'>
Even in failed case of pm_runtime_get_sync, the usage_count
is incremented. In order to keep the usage_count with correct
value and runtime power management to behave correctly, call
pm_runtime_put_noidle in such case.

Signed-off-by: Liu Chuansheng &lt;chuansheng.liu@intel.com&gt;
Signed-off-by: Li Fei &lt;fei.li@intel.com&gt;
Acked-by: Ohad Ben-Cohen &lt;ohad@wizery.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Even in failed case of pm_runtime_get_sync, the usage_count
is incremented. In order to keep the usage_count with correct
value and runtime power management to behave correctly, call
pm_runtime_put_noidle in such case.

Signed-off-by: Liu Chuansheng &lt;chuansheng.liu@intel.com&gt;
Signed-off-by: Li Fei &lt;fei.li@intel.com&gt;
Acked-by: Ohad Ben-Cohen &lt;ohad@wizery.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: fix performance regression initializing MMC host controllers</title>
<updated>2013-04-12T18:08:07+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-04-04T13:41:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0d3e3350d5871c53464be4c92d57198744247005'/>
<id>0d3e3350d5871c53464be4c92d57198744247005</id>
<content type='text'>
Commit fa5501890d8974301042e0202d342a6cbe8609f4 introduced a performance
regression by adding mmc_power_up() to mmc_start_host().  mmc_power_up()
is not necessary to host controller initialization, it is part of card
initialization and is performed anyway asynchronously.

This patch allows a driver to leave the power up in asynchronous code
(as it was before).

On my current target platform this reduces driver initialization from:

[    1.313220] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 102008 usecs

to this:

[    1.217209] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 8331 usecs

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit fa5501890d8974301042e0202d342a6cbe8609f4 introduced a performance
regression by adding mmc_power_up() to mmc_start_host().  mmc_power_up()
is not necessary to host controller initialization, it is part of card
initialization and is performed anyway asynchronously.

This patch allows a driver to leave the power up in asynchronous code
(as it was before).

On my current target platform this reduces driver initialization from:

[    1.313220] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 102008 usecs

to this:

[    1.217209] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 8331 usecs

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "mmc: core: wait while adding MMC host to ensure root mounts successfully"</title>
<updated>2013-04-12T18:07:50+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-04-04T13:41:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f9a94e0a3f18ae4c0245d4a16d0ee20e93fd7bad'/>
<id>f9a94e0a3f18ae4c0245d4a16d0ee20e93fd7bad</id>
<content type='text'>
This reverts commit 3500ed90b26a9935b943b5e2e4cd3226600d6b58.

The reverted patch caused a significant performance regression when
booting with the root file system on eMMC.

Before the patch:

[    1.625623] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

After the patch:

[    1.935851] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

That was an addition of 310 ms which is a 19% performance degradation.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 3500ed90b26a9935b943b5e2e4cd3226600d6b58.

The reverted patch caused a significant performance regression when
booting with the root file system on eMMC.

Before the patch:

[    1.625623] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

After the patch:

[    1.935851] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

That was an addition of 310 ms which is a 19% performance degradation.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Fix bit width test failing on old eMMC cards</title>
<updated>2013-04-04T19:33:29+00:00</updated>
<author>
<name>Philip Rakity</name>
<email>prakity@yahoo.com</email>
</author>
<published>2013-04-04T19:18:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=836dc2fe89c968c10cada87e0dfae6626f8f9da3'/>
<id>836dc2fe89c968c10cada87e0dfae6626f8f9da3</id>
<content type='text'>
PARTITION_SUPPORT needs to be set before doing the compare on version
number so the bit width test does not get invalid data.  Before this
patch, a Sandisk iNAND eMMC card would detect 1-bit width although
the hardware supports 4-bit.

Only affects old emmc devices - pre 4.4 devices.

Reported-by: Elad Yi &lt;elad.yi@gmail.com&gt;
Signed-off-by: Philip Rakity &lt;prakity@yahoo.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PARTITION_SUPPORT needs to be set before doing the compare on version
number so the bit width test does not get invalid data.  Before this
patch, a Sandisk iNAND eMMC card would detect 1-bit width although
the hardware supports 4-bit.

Only affects old emmc devices - pre 4.4 devices.

Reported-by: Elad Yi &lt;elad.yi@gmail.com&gt;
Signed-off-by: Philip Rakity &lt;prakity@yahoo.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: wait while adding MMC host to ensure root mounts successfully</title>
<updated>2013-03-22T17:03:29+00:00</updated>
<author>
<name>Sergey Yanovich</name>
<email>ynvich@gmail.com</email>
</author>
<published>2013-03-14T01:23:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3500ed90b26a9935b943b5e2e4cd3226600d6b58'/>
<id>3500ed90b26a9935b943b5e2e4cd3226600d6b58</id>
<content type='text'>
MMC hosts are added asynchronously. We need to wait until detect returns to
avoid failed root filesystem mounts.

VFS: Cannot open root device "mmcblk0p1" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
mmc0: host does not support reading read-only switch. assuming write-enable.
1f00             256 mtdblock0  (driver?)
1f01             256 mtdblock1  (driver?)
1f02            2560 mtdblock2 mmc0: new SDHC card at address b368
 (driver?)
1f03           29696 mtdblock3  (driver?)
1f04           16384 mtdblock4 mmcblk0: mmc0:b368 USD   3.72 GiB
 (driver?)
 mmcblk0: p1
b300         3910656 mmcblk0  driver: mmcblk
  b301         3906560 mmcblk0p1 00000000-01
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Signed-off-by: Sergey Yanovich &lt;ynvich@gmail.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
MMC hosts are added asynchronously. We need to wait until detect returns to
avoid failed root filesystem mounts.

VFS: Cannot open root device "mmcblk0p1" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
mmc0: host does not support reading read-only switch. assuming write-enable.
1f00             256 mtdblock0  (driver?)
1f01             256 mtdblock1  (driver?)
1f02            2560 mtdblock2 mmc0: new SDHC card at address b368
 (driver?)
1f03           29696 mtdblock3  (driver?)
1f04           16384 mtdblock4 mmcblk0: mmc0:b368 USD   3.72 GiB
 (driver?)
 mmcblk0: p1
b300         3910656 mmcblk0  driver: mmcblk
  b301         3906560 mmcblk0p1 00000000-01
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Signed-off-by: Sergey Yanovich &lt;ynvich@gmail.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: sdio: bind acpi with sdio function device</title>
<updated>2013-03-22T16:26:54+00:00</updated>
<author>
<name>Aaron Lu</name>
<email>aaron.lu@intel.com</email>
</author>
<published>2013-03-05T03:24:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=eed222aca8d077af3600b651176f6fd04d95cce1'/>
<id>eed222aca8d077af3600b651176f6fd04d95cce1</id>
<content type='text'>
ACPI spec 5 defined the _ADR encoding for sdio bus as:
High word - slot number (0 based)
Low word  - function number

This patch adds support for binding sdio function device with acpi node,
and if successful, involve acpi into its power management.

Signed-off-by: Aaron Lu &lt;aaron.lu@intel.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ACPI spec 5 defined the _ADR encoding for sdio bus as:
High word - slot number (0 based)
Low word  - function number

This patch adds support for binding sdio function device with acpi node,
and if successful, involve acpi into its power management.

Signed-off-by: Aaron Lu &lt;aaron.lu@intel.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: enhance card removal judgement for slow removal</title>
<updated>2013-03-22T16:23:34+00:00</updated>
<author>
<name>Kevin Liu</name>
<email>kliu5@marvell.com</email>
</author>
<published>2013-02-28T07:29:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1450734ec61cda7bbb77afc8cb412b9d64c62d9a'/>
<id>1450734ec61cda7bbb77afc8cb412b9d64c62d9a</id>
<content type='text'>
Function _mmc_detect_card_removed will be called to know whether
the card is still present when host-&gt;bus_ops-&gt;detect is called.
In current code, the return value of this function generally only
depend on the result of sending cmd13 to card, which may not safe
for card with detection support like slot gpio detection.
Because the communication status between host and card may out of
sync with the detect status if remove the card slowly or hands shake
during the process. The direct reason is the async between card
detect switch and card/slot pad contaction in hardware, which is
defined by spec.

The spec define card insert/remove sequence as below (both standard size
SD card and MicroSD card have the same sequence):
"Part 1 Standard Size SD Card Mechanical Addendum Ver4.00 Final,
Appendix C: Card Detection Switch" (Take normally open type as example)
a)SD card insertion sequence:
  The card detection switch should be turned on after all SD card
  contact pads are connected to the host connector contact pads.
b)SD removal sequence:
  The card detection switch should be turned off when the SD card
  is just going to be removed and before any SD card contact pad is
  disconnected from the host connector contact pad.

Below is the sequence when this issue occur (Take slot gpio detection
as example and remove the card slowly during the process):
1. gpio level changed and card detect interrupt triggered.
2. mmc_rescan was launched.
3. the card pads were still contacted with the slot pads because of slow
   removal. So _mmc_detect_card_removed and mmc_rescan think card was
   still present (cmd13 succeed).
4. card pads were discontacted from the card slot pads.
So the card was actually removed finally but the card removal event
has been missed by system.
The interval length between step 1 and step 4 depends on the
card removal speed. If it's longer than the detect work schedule
delay which is 200ms, this issue will likely happen.

This patch add the card detect status check in function
_mmc_detect_card_removed if cmd13 check succeed and host-&gt;ops-&gt;get_cd
provided. If get_cd detect no card present then schedule another detect
work 200ms later.

Signed-off-by: Kevin Liu &lt;kliu5@marvell.com&gt;
Tested-by: Johan Rudholm &lt;johan.rudholm@stericsson.com&gt;
Reviewed-by: Philip Rakity &lt;prakity@nvidia.com&gt;
Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
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Function _mmc_detect_card_removed will be called to know whether
the card is still present when host-&gt;bus_ops-&gt;detect is called.
In current code, the return value of this function generally only
depend on the result of sending cmd13 to card, which may not safe
for card with detection support like slot gpio detection.
Because the communication status between host and card may out of
sync with the detect status if remove the card slowly or hands shake
during the process. The direct reason is the async between card
detect switch and card/slot pad contaction in hardware, which is
defined by spec.

The spec define card insert/remove sequence as below (both standard size
SD card and MicroSD card have the same sequence):
"Part 1 Standard Size SD Card Mechanical Addendum Ver4.00 Final,
Appendix C: Card Detection Switch" (Take normally open type as example)
a)SD card insertion sequence:
  The card detection switch should be turned on after all SD card
  contact pads are connected to the host connector contact pads.
b)SD removal sequence:
  The card detection switch should be turned off when the SD card
  is just going to be removed and before any SD card contact pad is
  disconnected from the host connector contact pad.

Below is the sequence when this issue occur (Take slot gpio detection
as example and remove the card slowly during the process):
1. gpio level changed and card detect interrupt triggered.
2. mmc_rescan was launched.
3. the card pads were still contacted with the slot pads because of slow
   removal. So _mmc_detect_card_removed and mmc_rescan think card was
   still present (cmd13 succeed).
4. card pads were discontacted from the card slot pads.
So the card was actually removed finally but the card removal event
has been missed by system.
The interval length between step 1 and step 4 depends on the
card removal speed. If it's longer than the detect work schedule
delay which is 200ms, this issue will likely happen.

This patch add the card detect status check in function
_mmc_detect_card_removed if cmd13 check succeed and host-&gt;ops-&gt;get_cd
provided. If get_cd detect no card present then schedule another detect
work 200ms later.

Signed-off-by: Kevin Liu &lt;kliu5@marvell.com&gt;
Tested-by: Johan Rudholm &lt;johan.rudholm@stericsson.com&gt;
Reviewed-by: Philip Rakity &lt;prakity@nvidia.com&gt;
Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Chris Ball &lt;cjb@laptop.org&gt;
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