<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/mmc, branch v5.4-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>mmc: host: sdhci-pci: Add Genesys Logic GL975x support</title>
<updated>2019-09-27T18:48:20+00:00</updated>
<author>
<name>Ben Chuang</name>
<email>ben.chuang@genesyslogic.com.tw</email>
</author>
<published>2019-09-11T07:23:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e51df6ce668a8f75ce27f83ce0f60103c568c375'/>
<id>e51df6ce668a8f75ce27f83ce0f60103c568c375</id>
<content type='text'>
Add support for the GL9750 and GL9755 chipsets.

Enable v4 mode and wait 5ms after set 1.8V signal enable for GL9750/
GL9755. Fix the value of SDHCI_MAX_CURRENT register and use the vendor
tuning flow for GL9750.

Co-developed-by: Michael K Johnson &lt;johnsonm@danlj.org&gt;
Signed-off-by: Michael K Johnson &lt;johnsonm@danlj.org&gt;
Signed-off-by: Ben Chuang &lt;ben.chuang@genesyslogic.com.tw&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for the GL9750 and GL9755 chipsets.

Enable v4 mode and wait 5ms after set 1.8V signal enable for GL9750/
GL9755. Fix the value of SDHCI_MAX_CURRENT register and use the vendor
tuning flow for GL9750.

Co-developed-by: Michael K Johnson &lt;johnsonm@danlj.org&gt;
Signed-off-by: Michael K Johnson &lt;johnsonm@danlj.org&gt;
Signed-off-by: Ben Chuang &lt;ben.chuang@genesyslogic.com.tw&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: tegra: Implement -&gt;set_dma_mask()</title>
<updated>2019-09-27T18:30:13+00:00</updated>
<author>
<name>Nicolin Chen</name>
<email>nicoleotsuka@gmail.com</email>
</author>
<published>2019-09-23T10:08:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b960bc448a252428bacca271f3416a8bda3b599b'/>
<id>b960bc448a252428bacca271f3416a8bda3b599b</id>
<content type='text'>
The SDHCI controller on Tegra186 supports 40-bit addressing, which is
usually enough to address all of system memory. However, if the SDHCI
controller is behind an IOMMU, the address space can go beyond. This
happens on Tegra186 and later where the ARM SMMU has an input address
space of 48 bits. If the DMA API is backed by this ARM SMMU, the top-
down IOVA allocator will cause IOV addresses to be returned that the
SDHCI controller cannot access.

Unfortunately, prior to the introduction of the -&gt;set_dma_mask() host
operation, the SDHCI core would set either a 64-bit DMA mask if the
controller claimed to support 64-bit addressing, or a 32-bit DMA mask
otherwise.

Since the full 64 bits cannot be addressed on Tegra, this had to be
worked around in commit 68481a7e1c84 ("mmc: tegra: Mark 64 bit dma
broken on Tegra186") by setting the SDHCI_QUIRK2_BROKEN_64_BIT_DMA
quirk, which effectively restricts the DMA mask to 32 bits.

One disadvantage of this is that dma_map_*() APIs will now try to use
the swiotlb to bounce DMA to addresses beyond of the controller's DMA
mask. This in turn caused degraded performance and can lead to
situations where the swiotlb buffer is exhausted, which in turn leads
to DMA transfers to fail.

With the recent introduction of the -&gt;set_dma_mask() host operation,
this can now be properly fixed. For each generation of Tegra, the exact
supported DMA mask can be configured. This kills two birds with one
stone: it avoids the use of bounce buffers because system memory never
exceeds the addressable memory range of the SDHCI controllers on these
devices, and at the same time when an IOMMU is involved, it prevents
IOV addresses from being allocated beyond the addressible range of the
controllers.

Since the DMA mask is now properly handled, the 64-bit DMA quirk can be
removed.

Signed-off-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
[treding@nvidia.com: provide more background in commit message]
Tested-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org # v4.15 +
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The SDHCI controller on Tegra186 supports 40-bit addressing, which is
usually enough to address all of system memory. However, if the SDHCI
controller is behind an IOMMU, the address space can go beyond. This
happens on Tegra186 and later where the ARM SMMU has an input address
space of 48 bits. If the DMA API is backed by this ARM SMMU, the top-
down IOVA allocator will cause IOV addresses to be returned that the
SDHCI controller cannot access.

Unfortunately, prior to the introduction of the -&gt;set_dma_mask() host
operation, the SDHCI core would set either a 64-bit DMA mask if the
controller claimed to support 64-bit addressing, or a 32-bit DMA mask
otherwise.

Since the full 64 bits cannot be addressed on Tegra, this had to be
worked around in commit 68481a7e1c84 ("mmc: tegra: Mark 64 bit dma
broken on Tegra186") by setting the SDHCI_QUIRK2_BROKEN_64_BIT_DMA
quirk, which effectively restricts the DMA mask to 32 bits.

One disadvantage of this is that dma_map_*() APIs will now try to use
the swiotlb to bounce DMA to addresses beyond of the controller's DMA
mask. This in turn caused degraded performance and can lead to
situations where the swiotlb buffer is exhausted, which in turn leads
to DMA transfers to fail.

With the recent introduction of the -&gt;set_dma_mask() host operation,
this can now be properly fixed. For each generation of Tegra, the exact
supported DMA mask can be configured. This kills two birds with one
stone: it avoids the use of bounce buffers because system memory never
exceeds the addressable memory range of the SDHCI controllers on these
devices, and at the same time when an IOMMU is involved, it prevents
IOV addresses from being allocated beyond the addressible range of the
controllers.

Since the DMA mask is now properly handled, the 64-bit DMA quirk can be
removed.

Signed-off-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
[treding@nvidia.com: provide more background in commit message]
Tested-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org # v4.15 +
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: sdhci: Let drivers define their DMA mask</title>
<updated>2019-09-27T18:30:13+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2019-09-23T10:08:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4ee7dde4c777f14cb0f98dd201491bf6cc15899b'/>
<id>4ee7dde4c777f14cb0f98dd201491bf6cc15899b</id>
<content type='text'>
Add host operation -&gt;set_dma_mask() so that drivers can define their own
DMA masks.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org # v4.15 +
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add host operation -&gt;set_dma_mask() so that drivers can define their own
DMA masks.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org # v4.15 +
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: sdhci-of-esdhc: set DMA snooping based on DMA coherence</title>
<updated>2019-09-27T18:30:13+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2019-09-22T10:26:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=121bd08b029e03404c451bb237729cdff76eafed'/>
<id>121bd08b029e03404c451bb237729cdff76eafed</id>
<content type='text'>
We must not unconditionally set the DMA snoop bit; if the DMA API is
assuming that the device is not DMA coherent, and the device snoops the
CPU caches, the device can see stale cache lines brought in by
speculative prefetch.

This leads to the device seeing stale data, potentially resulting in
corrupted data transfers.  Commonly, this results in a descriptor fetch
error such as:

mmc0: ADMA error
mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
mmc0: sdhci: Sys addr:  0x00000000 | Version:  0x00002202
mmc0: sdhci: Blk size:  0x00000008 | Blk cnt:  0x00000001
mmc0: sdhci: Argument:  0x00000000 | Trn mode: 0x00000013
mmc0: sdhci: Present:   0x01f50008 | Host ctl: 0x00000038
mmc0: sdhci: Power:     0x00000003 | Blk gap:  0x00000000
mmc0: sdhci: Wake-up:   0x00000000 | Clock:    0x000040d8
mmc0: sdhci: Timeout:   0x00000003 | Int stat: 0x00000001
mmc0: sdhci: Int enab:  0x037f108f | Sig enab: 0x037f108b
mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00002202
mmc0: sdhci: Caps:      0x35fa0000 | Caps_1:   0x0000af00
mmc0: sdhci: Cmd:       0x0000333a | Max curr: 0x00000000
mmc0: sdhci: Resp[0]:   0x00000920 | Resp[1]:  0x001d8a33
mmc0: sdhci: Resp[2]:   0x325b5900 | Resp[3]:  0x3f400e00
mmc0: sdhci: Host ctl2: 0x00000000
mmc0: sdhci: ADMA Err:  0x00000009 | ADMA Ptr: 0x000000236d43820c
mmc0: sdhci: ============================================
mmc0: error -5 whilst initialising SD card

but can lead to other errors, and potentially direct the SDHCI
controller to read/write data to other memory locations (e.g. if a valid
descriptor is visible to the device in a stale cache line.)

Fix this by ensuring that the DMA snoop bit corresponds with the
behaviour of the DMA API.  Since the driver currently only supports DT,
use of_dma_is_coherent().  Note that device_get_dma_attr() can not be
used as that risks re-introducing this bug if/when the driver is
converted to ACPI.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We must not unconditionally set the DMA snoop bit; if the DMA API is
assuming that the device is not DMA coherent, and the device snoops the
CPU caches, the device can see stale cache lines brought in by
speculative prefetch.

This leads to the device seeing stale data, potentially resulting in
corrupted data transfers.  Commonly, this results in a descriptor fetch
error such as:

mmc0: ADMA error
mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
mmc0: sdhci: Sys addr:  0x00000000 | Version:  0x00002202
mmc0: sdhci: Blk size:  0x00000008 | Blk cnt:  0x00000001
mmc0: sdhci: Argument:  0x00000000 | Trn mode: 0x00000013
mmc0: sdhci: Present:   0x01f50008 | Host ctl: 0x00000038
mmc0: sdhci: Power:     0x00000003 | Blk gap:  0x00000000
mmc0: sdhci: Wake-up:   0x00000000 | Clock:    0x000040d8
mmc0: sdhci: Timeout:   0x00000003 | Int stat: 0x00000001
mmc0: sdhci: Int enab:  0x037f108f | Sig enab: 0x037f108b
mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00002202
mmc0: sdhci: Caps:      0x35fa0000 | Caps_1:   0x0000af00
mmc0: sdhci: Cmd:       0x0000333a | Max curr: 0x00000000
mmc0: sdhci: Resp[0]:   0x00000920 | Resp[1]:  0x001d8a33
mmc0: sdhci: Resp[2]:   0x325b5900 | Resp[3]:  0x3f400e00
mmc0: sdhci: Host ctl2: 0x00000000
mmc0: sdhci: ADMA Err:  0x00000009 | ADMA Ptr: 0x000000236d43820c
mmc0: sdhci: ============================================
mmc0: error -5 whilst initialising SD card

but can lead to other errors, and potentially direct the SDHCI
controller to read/write data to other memory locations (e.g. if a valid
descriptor is visible to the device in a stale cache line.)

Fix this by ensuring that the DMA snoop bit corresponds with the
behaviour of the DMA API.  Since the driver currently only supports DT,
use of_dma_is_coherent().  Note that device_get_dma_attr() can not be
used as that risks re-introducing this bug if/when the driver is
converted to ACPI.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: sdhci: improve ADMA error reporting</title>
<updated>2019-09-27T18:30:13+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2019-09-22T10:26:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d1c536e3177390da43d99f20143b810c35433d1f'/>
<id>d1c536e3177390da43d99f20143b810c35433d1f</id>
<content type='text'>
ADMA errors are potentially data corrupting events; although we print
the register state, we do not usefully print the ADMA descriptors.
Worse than that, we print them by referencing their virtual address
which is meaningless when the register state gives us the DMA address
of the failing descriptor.

Print the ADMA descriptors giving their DMA addresses rather than their
virtual addresses, and print them using SDHCI_DUMP() rather than DBG().

We also do not show the correct value of the interrupt status register;
the register dump shows the current value, after we have cleared the
pending interrupts we are going to service.  What is more useful is to
print the interrupts that _were_ pending at the time the ADMA error was
encountered.  Fix that too.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ADMA errors are potentially data corrupting events; although we print
the register state, we do not usefully print the ADMA descriptors.
Worse than that, we print them by referencing their virtual address
which is meaningless when the register state gives us the DMA address
of the failing descriptor.

Print the ADMA descriptors giving their DMA addresses rather than their
virtual addresses, and print them using SDHCI_DUMP() rather than DBG().

We also do not show the correct value of the interrupt status register;
the register dump shows the current value, after we have cleared the
pending interrupts we are going to service.  What is more useful is to
print the interrupts that _were_ pending at the time the ADMA error was
encountered.  Fix that too.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping</title>
<updated>2019-09-19T20:27:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-09-19T20:27:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=671df189537883f36cf9c7d4f9495bfac0f86627'/>
<id>671df189537883f36cf9c7d4f9495bfac0f86627</id>
<content type='text'>
Pull dma-mapping updates from Christoph Hellwig:

 - add dma-mapping and block layer helpers to take care of IOMMU merging
   for mmc plus subsequent fixups (Yoshihiro Shimoda)

 - rework handling of the pgprot bits for remapping (me)

 - take care of the dma direct infrastructure for swiotlb-xen (me)

 - improve the dma noncoherent remapping infrastructure (me)

 - better defaults for -&gt;mmap, -&gt;get_sgtable and -&gt;get_required_mask
   (me)

 - cleanup mmaping of coherent DMA allocations (me)

 - various misc cleanups (Andy Shevchenko, me)

* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
  mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
  mmc: queue: Fix bigger segments usage
  arm64: use asm-generic/dma-mapping.h
  swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
  swiotlb-xen: simplify cache maintainance
  swiotlb-xen: use the same foreign page check everywhere
  swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
  xen: remove the exports for xen_{create,destroy}_contiguous_region
  xen/arm: remove xen_dma_ops
  xen/arm: simplify dma_cache_maint
  xen/arm: use dev_is_dma_coherent
  xen/arm: consolidate page-coherent.h
  xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
  arm: remove wrappers for the generic dma remap helpers
  dma-mapping: introduce a dma_common_find_pages helper
  dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
  vmalloc: lift the arm flag for coherent mappings to common code
  dma-mapping: provide a better default -&gt;get_required_mask
  dma-mapping: remove the dma_declare_coherent_memory export
  remoteproc: don't allow modular build
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull dma-mapping updates from Christoph Hellwig:

 - add dma-mapping and block layer helpers to take care of IOMMU merging
   for mmc plus subsequent fixups (Yoshihiro Shimoda)

 - rework handling of the pgprot bits for remapping (me)

 - take care of the dma direct infrastructure for swiotlb-xen (me)

 - improve the dma noncoherent remapping infrastructure (me)

 - better defaults for -&gt;mmap, -&gt;get_sgtable and -&gt;get_required_mask
   (me)

 - cleanup mmaping of coherent DMA allocations (me)

 - various misc cleanups (Andy Shevchenko, me)

* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
  mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
  mmc: queue: Fix bigger segments usage
  arm64: use asm-generic/dma-mapping.h
  swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
  swiotlb-xen: simplify cache maintainance
  swiotlb-xen: use the same foreign page check everywhere
  swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
  xen: remove the exports for xen_{create,destroy}_contiguous_region
  xen/arm: remove xen_dma_ops
  xen/arm: simplify dma_cache_maint
  xen/arm: use dev_is_dma_coherent
  xen/arm: consolidate page-coherent.h
  xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
  arm: remove wrappers for the generic dma remap helpers
  dma-mapping: introduce a dma_common_find_pages helper
  dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
  vmalloc: lift the arm flag for coherent mappings to common code
  dma-mapping: provide a better default -&gt;get_required_mask
  dma-mapping: remove the dma_declare_coherent_memory export
  remoteproc: don't allow modular build
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'fixes' into next</title>
<updated>2019-09-13T11:57:37+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-09-13T11:57:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b46119796721301e410a357b91195eed46980ea6'/>
<id>b46119796721301e410a357b91195eed46980ea6</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: tmio: Fixup runtime PM management during remove</title>
<updated>2019-09-13T11:49:09+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-09-13T09:20:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=87b5d602a1cc76169b8d81ec2c74c8d95d9350dc'/>
<id>87b5d602a1cc76169b8d81ec2c74c8d95d9350dc</id>
<content type='text'>
Accessing the device when it may be runtime suspended is a bug, which is
the case in tmio_mmc_host_remove(). Let's fix the behaviour.

Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Accessing the device when it may be runtime suspended is a bug, which is
the case in tmio_mmc_host_remove(). Let's fix the behaviour.

Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: tmio: Fixup runtime PM management during probe</title>
<updated>2019-09-13T11:49:04+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-09-13T09:19:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=aa86f1a3887523d78bfadd1c4e4df8f919336511'/>
<id>aa86f1a3887523d78bfadd1c4e4df8f919336511</id>
<content type='text'>
The tmio_mmc_host_probe() calls pm_runtime_set_active() to update the
runtime PM status of the device, as to make it reflect the current status
of the HW. This works fine for most cases, but unfortunate not for all.
Especially, there is a generic problem when the device has a genpd attached
and that genpd have the -&gt;start|stop() callbacks assigned.

More precisely, if the driver calls pm_runtime_set_active() during
-&gt;probe(), genpd does not get to invoke the -&gt;start() callback for it,
which means the HW isn't really fully powered on. Furthermore, in the next
phase, when the device becomes runtime suspended, genpd will invoke the
-&gt;stop() callback for it, potentially leading to usage count imbalance
problems, depending on what's implemented behind the callbacks of course.

To fix this problem, convert to call pm_runtime_get_sync() from
tmio_mmc_host_probe() rather than pm_runtime_set_active(). Additionally, to
avoid bumping usage counters and unnecessary re-initializing the HW the
first time the tmio driver's -&gt;runtime_resume() callback is called,
introduce a state flag to keeping track of this.

Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The tmio_mmc_host_probe() calls pm_runtime_set_active() to update the
runtime PM status of the device, as to make it reflect the current status
of the HW. This works fine for most cases, but unfortunate not for all.
Especially, there is a generic problem when the device has a genpd attached
and that genpd have the -&gt;start|stop() callbacks assigned.

More precisely, if the driver calls pm_runtime_set_active() during
-&gt;probe(), genpd does not get to invoke the -&gt;start() callback for it,
which means the HW isn't really fully powered on. Furthermore, in the next
phase, when the device becomes runtime suspended, genpd will invoke the
-&gt;stop() callback for it, potentially leading to usage count imbalance
problems, depending on what's implemented behind the callbacks of course.

To fix this problem, convert to call pm_runtime_get_sync() from
tmio_mmc_host_probe() rather than pm_runtime_set_active(). Additionally, to
avoid bumping usage counters and unnecessary re-initializing the HW the
first time the tmio driver's -&gt;runtime_resume() callback is called,
introduce a state flag to keeping track of this.

Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "mmc: tmio: move runtime PM enablement to the driver implementations"</title>
<updated>2019-09-13T11:48:35+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-09-13T08:03:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8861474a105c91e812d38cd65d3be795c7f32c4f'/>
<id>8861474a105c91e812d38cd65d3be795c7f32c4f</id>
<content type='text'>
This reverts commit 7ff213193310ef8d0ee5f04f79d791210787ac2c.

It turns out that the above commit introduces other problems. For example,
calling pm_runtime_set_active() must not be done prior calling
pm_runtime_enable() as that makes it fail. This leads to additional
problems, such as clock enables being wrongly balanced.

Rather than fixing the problem on top, let's start over by doing a revert.

Fixes: 7ff213193310 ("mmc: tmio: move runtime PM enablement to the driver implementations")
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 7ff213193310ef8d0ee5f04f79d791210787ac2c.

It turns out that the above commit introduces other problems. For example,
calling pm_runtime_set_active() must not be done prior calling
pm_runtime_enable() as that makes it fail. This leads to additional
problems, such as clock enables being wrongly balanced.

Rather than fixing the problem on top, let's start over by doing a revert.

Fixes: 7ff213193310 ("mmc: tmio: move runtime PM enablement to the driver implementations")
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
