<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/mmc/core, branch v4.9.142</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>mmc: pwrseq: Use kmalloc_array instead of stack VLA</title>
<updated>2018-08-03T05:55:24+00:00</updated>
<author>
<name>Tobin C. Harding</name>
<email>me@tobin.cc</email>
</author>
<published>2018-03-26T06:33:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df157f60b9e7f12f30550254111c13c043d10529'/>
<id>df157f60b9e7f12f30550254111c13c043d10529</id>
<content type='text'>
[ Upstream commit 486e6661367b40f927aadbed73237693396cbf94 ]

The use of stack Variable Length Arrays needs to be avoided, as they
can be a vector for stack exhaustion, which can be both a runtime bug
(kernel Oops) or a security flaw (overwriting memory beyond the
stack). Also, in general, as code evolves it is easy to lose track of
how big a VLA can get. Thus, we can end up having runtime failures
that are hard to debug. As part of the directive[1] to remove all VLAs
from the kernel, and build with -Wvla.

Currently driver is using a VLA declared using the number of descriptors.  This
array is used to store integer values and is later used as an argument to
`gpiod_set_array_value_cansleep()` This can be avoided by using
`kmalloc_array()` to allocate memory for the array of integer values.  Memory is
free'd before return from function.

&gt;From the code it appears that it is safe to sleep so we can use GFP_KERNEL
(based _cansleep() suffix of function `gpiod_set_array_value_cansleep()`.

It can be expected that this patch will result in a small increase in overhead
due to the use of `kmalloc_array()`

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Tobin C. Harding &lt;me@tobin.cc&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 486e6661367b40f927aadbed73237693396cbf94 ]

The use of stack Variable Length Arrays needs to be avoided, as they
can be a vector for stack exhaustion, which can be both a runtime bug
(kernel Oops) or a security flaw (overwriting memory beyond the
stack). Also, in general, as code evolves it is easy to lose track of
how big a VLA can get. Thus, we can end up having runtime failures
that are hard to debug. As part of the directive[1] to remove all VLAs
from the kernel, and build with -Wvla.

Currently driver is using a VLA declared using the number of descriptors.  This
array is used to store integer values and is later used as an argument to
`gpiod_set_array_value_cansleep()` This can be avoided by using
`kmalloc_array()` to allocate memory for the array of integer values.  Memory is
free'd before return from function.

&gt;From the code it appears that it is safe to sleep so we can use GFP_KERNEL
(based _cansleep() suffix of function `gpiod_set_array_value_cansleep()`.

It can be expected that this patch will result in a small increase in overhead
due to the use of `kmalloc_array()`

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Tobin C. Harding &lt;me@tobin.cc&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: avoid removing non-removable hosts during suspend</title>
<updated>2018-03-24T10:00:24+00:00</updated>
<author>
<name>Daniel Drake</name>
<email>drake@endlessm.com</email>
</author>
<published>2017-12-12T10:49:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=963f3129a189213876200d46e5698638d44c5e11'/>
<id>963f3129a189213876200d46e5698638d44c5e11</id>
<content type='text'>
[ Upstream commit de8dcc3d2c0e08e5068ee1e26fc46415c15e3637 ]

The Weibu F3C MiniPC has an onboard AP6255 module, presenting
two SDIO functions on a single MMC host (Bluetooth/btsdio and
WiFi/brcmfmac), and the mmc layer correctly detects this as
non-removable.

After suspend/resume, the wifi and bluetooth interfaces disappear
and do not get probed again.

The conditions here are:

 1. During suspend, we reach mmc_pm_notify()

 2. mmc_pm_notify() calls mmc_sdio_pre_suspend() to see if we can
    suspend the SDIO host. However, mmc_sdio_pre_suspend() returns
    -ENOSYS because btsdio_driver does not have a suspend method.

 3. mmc_pm_notify() proceeds to remove the card

 4. Upon resume, mmc_rescan() does nothing with this host, because of
    the rescan_entered check which aims to only scan a non-removable
    device a single time (i.e. during boot).

Fix the loss of functionality by detecting that we are unable to
suspend a non-removable host, so avoid the forced removal in that
case. The comment above this function already indicates that this
code was only intended for removable devices.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit de8dcc3d2c0e08e5068ee1e26fc46415c15e3637 ]

The Weibu F3C MiniPC has an onboard AP6255 module, presenting
two SDIO functions on a single MMC host (Bluetooth/btsdio and
WiFi/brcmfmac), and the mmc layer correctly detects this as
non-removable.

After suspend/resume, the wifi and bluetooth interfaces disappear
and do not get probed again.

The conditions here are:

 1. During suspend, we reach mmc_pm_notify()

 2. mmc_pm_notify() calls mmc_sdio_pre_suspend() to see if we can
    suspend the SDIO host. However, mmc_sdio_pre_suspend() returns
    -ENOSYS because btsdio_driver does not have a suspend method.

 3. mmc_pm_notify() proceeds to remove the card

 4. Upon resume, mmc_rescan() does nothing with this host, because of
    the rescan_entered check which aims to only scan a non-removable
    device a single time (i.e. during boot).

Fix the loss of functionality by detecting that we are unable to
suspend a non-removable host, so avoid the forced removal in that
case. The comment above this function already indicates that this
code was only intended for removable devices.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: prepend 0x to OCR entry in sysfs</title>
<updated>2017-12-05T10:24:33+00:00</updated>
<author>
<name>Bastian Stender</name>
<email>bst@pengutronix.de</email>
</author>
<published>2017-11-28T08:24:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c814d6701b08fe58d6eb95641a089bde51afe951'/>
<id>c814d6701b08fe58d6eb95641a089bde51afe951</id>
<content type='text'>
commit c892b0d81705c566f575e489efc3c50762db1bde upstream.

The sysfs entry "ocr" was missing the 0x prefix to identify it as hex
formatted.

Fixes: 5fb06af7a33b ("mmc: core: Extend sysfs with OCR register")
Signed-off-by: Bastian Stender &lt;bst@pengutronix.de&gt;
[Ulf: Amended change to also cover SD-cards]
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c892b0d81705c566f575e489efc3c50762db1bde upstream.

The sysfs entry "ocr" was missing the 0x prefix to identify it as hex
formatted.

Fixes: 5fb06af7a33b ("mmc: core: Extend sysfs with OCR register")
Signed-off-by: Bastian Stender &lt;bst@pengutronix.de&gt;
[Ulf: Amended change to also cover SD-cards]
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Do not leave the block driver in a suspended state</title>
<updated>2017-12-05T10:24:33+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2017-11-21T13:42:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0bf4d0517667877c2b0955586070fd7198943896'/>
<id>0bf4d0517667877c2b0955586070fd7198943896</id>
<content type='text'>
commit ebe7dd45cf49e3b49cacbaace17f9f878f21fbea upstream.

The block driver must be resumed if the mmc bus fails to suspend the card.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ebe7dd45cf49e3b49cacbaace17f9f878f21fbea upstream.

The block driver must be resumed if the mmc bus fails to suspend the card.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: add driver strength selection when selecting hs400es</title>
<updated>2017-10-12T09:51:25+00:00</updated>
<author>
<name>Chanho Min</name>
<email>chanho.min@lge.com</email>
</author>
<published>2017-09-26T00:03:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d9aaef32f32c46b05c4d3bb96fe70e7c4346846e'/>
<id>d9aaef32f32c46b05c4d3bb96fe70e7c4346846e</id>
<content type='text'>
commit fb458864d9a78cc433fec7979acbe4078c82d7a8 upstream.

The driver strength selection is missed and required when selecting
hs400es. So, It is added here.

Fixes: 81ac2af65793ecf ("mmc: core: implement enhanced strobe support")
Signed-off-by: Hankyung Yu &lt;hankyung.yu@lge.com&gt;
Signed-off-by: Chanho Min &lt;chanho.min@lge.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chips.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit fb458864d9a78cc433fec7979acbe4078c82d7a8 upstream.

The driver strength selection is missed and required when selecting
hs400es. So, It is added here.

Fixes: 81ac2af65793ecf ("mmc: core: implement enhanced strobe support")
Signed-off-by: Hankyung Yu &lt;hankyung.yu@lge.com&gt;
Signed-off-by: Chanho Min &lt;chanho.min@lge.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chips.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: sdio: fix alignment issue in struct sdio_func</title>
<updated>2017-10-08T08:26:08+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2017-03-29T18:54:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=727a153435fa431c3c99cf5718976bdb73702d06'/>
<id>727a153435fa431c3c99cf5718976bdb73702d06</id>
<content type='text'>
[ Upstream commit 5ef1ecf060f28ecef313b5723f1fd39bf5a35f56 ]

Certain 64-bit systems (e.g. Amlogic Meson GX) require buffers to be
used for DMA to be 8-byte-aligned. struct sdio_func has an embedded
small DMA buffer not meeting this requirement.
When testing switching to descriptor chain mode in meson-gx driver
SDIO is broken therefore. Fix this by allocating the small DMA buffer
separately as kmalloc ensures that the returned memory area is
properly aligned for every basic data type.

Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Tested-by: Helmut Klein &lt;hgkr.klein@gmail.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5ef1ecf060f28ecef313b5723f1fd39bf5a35f56 ]

Certain 64-bit systems (e.g. Amlogic Meson GX) require buffers to be
used for DMA to be 8-byte-aligned. struct sdio_func has an embedded
small DMA buffer not meeting this requirement.
When testing switching to descriptor chain mode in meson-gx driver
SDIO is broken therefore. Fix this by allocating the small DMA buffer
separately as kmalloc ensures that the returned memory area is
properly aligned for every basic data type.

Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Tested-by: Helmut Klein &lt;hgkr.klein@gmail.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: mmc: correct the logic for setting HS400ES signal voltage</title>
<updated>2017-08-16T20:43:17+00:00</updated>
<author>
<name>Haibo Chen</name>
<email>haibo.chen@nxp.com</email>
</author>
<published>2017-08-08T10:54:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0a205d8145c22d83e24ada019b599a33f7bf68ed'/>
<id>0a205d8145c22d83e24ada019b599a33f7bf68ed</id>
<content type='text'>
commit 92ddd95919466de5d34f3cb43635da9a7f9ab814 upstream.

Change the default err value to -EINVAL, make sure the card only
has type EXT_CSD_CARD_TYPE_HS400_1_8V also do the signal voltage
setting when select hs400es mode.

Fixes: commit 1720d3545b77 ("mmc: core: switch to 1V8 or 1V2 for hs400es mode")
Signed-off-by: Haibo Chen &lt;haibo.chen@nxp.com&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chips.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 92ddd95919466de5d34f3cb43635da9a7f9ab814 upstream.

Change the default err value to -EINVAL, make sure the card only
has type EXT_CSD_CARD_TYPE_HS400_1_8V also do the signal voltage
setting when select hs400es mode.

Fixes: commit 1720d3545b77 ("mmc: core: switch to 1V8 or 1V2 for hs400es mode")
Signed-off-by: Haibo Chen &lt;haibo.chen@nxp.com&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chips.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Use device_property_read instead of of_property_read</title>
<updated>2017-08-11T15:49:31+00:00</updated>
<author>
<name>David Woods</name>
<email>dwoods@mellanox.com</email>
</author>
<published>2017-05-26T21:53:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e92add299fee14a3042960d723e074e8bd5c8412'/>
<id>e92add299fee14a3042960d723e074e8bd5c8412</id>
<content type='text'>
commit 73a47a9bb3e2c4a9c553c72456e63ab991b1a4d9 upstream.

Using the device_property interfaces allows mmc drivers to work
on platforms which run on either device tree or ACPI.

Signed-off-by: David Woods &lt;dwoods@mellanox.com&gt;
Reviewed-by: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 73a47a9bb3e2c4a9c553c72456e63ab991b1a4d9 upstream.

Using the device_property interfaces allows mmc drivers to work
on platforms which run on either device tree or ACPI.

Signed-off-by: David Woods &lt;dwoods@mellanox.com&gt;
Reviewed-by: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Fix access to HS400-ES devices</title>
<updated>2017-08-11T15:49:29+00:00</updated>
<author>
<name>Guenter Roeck</name>
<email>linux@roeck-us.net</email>
</author>
<published>2017-03-01T22:11:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=943281eb4ecfd5485abf41338c967d9ebf168ead'/>
<id>943281eb4ecfd5485abf41338c967d9ebf168ead</id>
<content type='text'>
commit 773dc118756b1f38766063e90e582016be868f09 upstream.

HS400-ES devices fail to initialize with the following error messages.

mmc1: power class selection to bus width 8 ddr 0 failed
mmc1: error -110 whilst initialising MMC card

This was seen on Samsung Chromebook Plus. Code analysis points to
commit 3d4ef329757c ("mmc: core: fix multi-bit bus width without
high-speed mode"), which attempts to set the bus width for all but
HS200 devices unconditionally. However, for HS400-ES, the bus width
is already selected.

Cc: Anssi Hannula &lt;anssi.hannula@bitwise.fi&gt;
Cc: Douglas Anderson &lt;dianders@chromium.org&gt;
Cc: Brian Norris &lt;briannorris@chromium.org&gt;
Fixes: 3d4ef329757c ("mmc: core: fix multi-bit bus width ...")
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reviewed-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chip.com&gt;
Tested-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 773dc118756b1f38766063e90e582016be868f09 upstream.

HS400-ES devices fail to initialize with the following error messages.

mmc1: power class selection to bus width 8 ddr 0 failed
mmc1: error -110 whilst initialising MMC card

This was seen on Samsung Chromebook Plus. Code analysis points to
commit 3d4ef329757c ("mmc: core: fix multi-bit bus width without
high-speed mode"), which attempts to set the bus width for all but
HS200 devices unconditionally. However, for HS400-ES, the bus width
is already selected.

Cc: Anssi Hannula &lt;anssi.hannula@bitwise.fi&gt;
Cc: Douglas Anderson &lt;dianders@chromium.org&gt;
Cc: Brian Norris &lt;briannorris@chromium.org&gt;
Fixes: 3d4ef329757c ("mmc: core: fix multi-bit bus width ...")
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reviewed-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Shawn Lin &lt;shawn.lin@rock-chip.com&gt;
Tested-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: fix multi-bit bus width without high-speed mode</title>
<updated>2017-02-23T16:44:35+00:00</updated>
<author>
<name>Anssi Hannula</name>
<email>anssi.hannula@bitwise.fi</email>
</author>
<published>2017-02-13T11:46:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef746a305de321a117723e664d57f7f4c2e2ac99'/>
<id>ef746a305de321a117723e664d57f7f4c2e2ac99</id>
<content type='text'>
commit 3d4ef329757cfd5e0b23cce97cdeca7e2df89c99 upstream.

Commit 577fb13199b1 ("mmc: rework selection of bus speed mode")
refactored bus width selection code to mmc_select_bus_width().

However, it also altered the behavior to not call the selection code in
non-high-speed modes anymore.

This causes 1-bit mode to always be used when the high-speed mode is not
enabled, even though 4-bit and 8-bit bus are valid bus widths in the
backwards-compatibility (legacy) mode as well (see e.g. 5.3.2 Bus Speed
Modes in JEDEC 84-B50). This results in a significant regression in
transfer speeds.

Fix the code to allow 4-bit and 8-bit widths even without high-speed
mode, as before.

Tested with a Zynq-7000 PicoZed 7020 board.

Fixes: 577fb13199b1 ("mmc: rework selection of bus speed mode")
Signed-off-by: Anssi Hannula &lt;anssi.hannula@bitwise.fi&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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commit 3d4ef329757cfd5e0b23cce97cdeca7e2df89c99 upstream.

Commit 577fb13199b1 ("mmc: rework selection of bus speed mode")
refactored bus width selection code to mmc_select_bus_width().

However, it also altered the behavior to not call the selection code in
non-high-speed modes anymore.

This causes 1-bit mode to always be used when the high-speed mode is not
enabled, even though 4-bit and 8-bit bus are valid bus widths in the
backwards-compatibility (legacy) mode as well (see e.g. 5.3.2 Bus Speed
Modes in JEDEC 84-B50). This results in a significant regression in
transfer speeds.

Fix the code to allow 4-bit and 8-bit widths even without high-speed
mode, as before.

Tested with a Zynq-7000 PicoZed 7020 board.

Fixes: 577fb13199b1 ("mmc: rework selection of bus speed mode")
Signed-off-by: Anssi Hannula &lt;anssi.hannula@bitwise.fi&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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