linux-toradex.git/drivers/memory/tegra/tegra20-emc.c, branch v6.14-rc2

memory: tegra20-emc: fix an OF node reference bug in tegra_emc_find_node_by_ram_code()

2024-12-22T10:02:39+00:00

As of_find_node_by_name() release the reference of the argument device
node, tegra_emc_find_node_by_ram_code() releases some device nodes while
still in use, resulting in possible UAFs. According to the bindings and
the in-tree DTS files, the "emc-tables" node is always device's child
node with the property "nvidia,use-ram-code", and the "lpddr2" node is a
child of the "emc-tables" node. Thus utilize the
for_each_child_of_node() macro and of_get_child_by_name() instead of
of_find_node_by_name() to simplify the code.

This bug was found by an experimental verification tool that I am
developing.

Fixes: 96e5da7c8424 ("memory: tegra: Introduce Tegra20 EMC driver")
Signed-off-by: Joe Hattori 
Link: https://lore.kernel.org/r/20241217091434.1993597-1-joe@pf.is.s.u-tokyo.ac.jp
Link: https://lore.kernel.org/r/20241218024415.2494267-3-joe@pf.is.s.u-tokyo.ac.jp
[krzysztof: applied v1, adjust the commit msg to incorporate v2 parts]
Signed-off-by: Krzysztof Kozlowski

memory: tegra20-emc: simplify with scoped for each OF child loop

2024-08-21T11:23:35+00:00

Use scoped for_each_child_of_node_scoped() when iterating over device
nodes to make code a bit simpler.

Reviewed-by: Jonathan Cameron 
Link: https://lore.kernel.org/r/20240816-cleanup-h-of-node-put-memory-v2-9-9eed0ee16b78@linaro.org
Signed-off-by: Krzysztof Kozlowski

interconnect: constify of_phandle_args in xlate

2024-02-25T22:38:17+00:00

The xlate callbacks are supposed to translate of_phandle_args to proper
provider without modifying the of_phandle_args.  Make the argument
pointer to const for code safety and readability.

Acked-by: Konrad Dybcio 
Acked-by: Thierry Reding  # Tegra
Signed-off-by: Krzysztof Kozlowski 
Acked-by: Alim Akhtar  # Samsung
Link: https://lore.kernel.org/r/20240220072213.35779-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Georgi Djakov

memory: tegra20-emc: fix interconnect registration race

2023-03-13T19:13:48+00:00

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: d5ef16ba5fbe ("memory: tegra20: Support interconnect framework")
Cc: stable@vger.kernel.org      # 5.11
Cc: Dmitry Osipenko 
Acked-by: Krzysztof Kozlowski 
Signed-off-by: Johan Hovold 
Link: https://lore.kernel.org/r/20230306075651.2449-20-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov

memory: tegra20-emc: use DEFINE_SHOW_ATTRIBUTE to simplify code

2022-10-17T21:49:17+00:00

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.
No functional change.

Signed-off-by: Liu Shixin 
Signed-off-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20220926130025.1061373-2-liushixin2@huawei.com

memory: tegra20-emc: Correct memory device mask

2022-01-27T09:40:35+00:00

Memory chip select is swapped when we read mode register, correct it.
We didn't have devices that use a single LPDDR chip and both chips are
always identical, hence this change is just a minor improvement.

Fixes: 131dd9a436d8 ("memory: tegra20-emc: Support matching timings by LPDDR2 configuration")
Signed-off-by: Dmitry Osipenko 
Link: https://lore.kernel.org/r/20211222043215.28237-2-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski

memory: tegra20-emc: Add runtime dependency on devfreq governor module

2021-10-21T09:18:08+00:00

Tegra20 EMC driver uses simple devfreq governor. Add simple devfreq
governor to the list of the Tegra20 EMC driver module softdeps to allow
userspace initramfs tools like dracut to automatically pull the devfreq
module into ramfs image together with the EMC module.

Reported-by: Nicolas Chauvet 
Suggested-by: Nicolas Chauvet 
Signed-off-by: Dmitry Osipenko 
Link: https://lore.kernel.org/r/20211019231524.888-1-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski

memory: tegra20-emc: Support matching timings by LPDDR2 configuration

2021-10-15T07:52:47+00:00

ASUS Transformer TF101 doesn't provide RAM code and in this case memory
timings should be selected based on identity information read out from
SDRAM chip. Support matching timings by LPDDR2 configuration.

Signed-off-by: Dmitry Osipenko 
Link: https://lore.kernel.org/r/20211006224659.21434-10-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski

memory: tegra: Delete dead debugfs checking code

2021-06-10T07:18:15+00:00

The debugfs_create_dir() function does not return NULL, it returns error
pointers.  But in normal situations like this where the caller is not
dereferencing "emc->debugfs.root" then we are not supposed to check the
return.  So instead of fixing these checks, we should delete them.

Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/YMCQDTSyG8UuQoh0@mwanda
Signed-off-by: Krzysztof Kozlowski

memory: tegra20-emc: Use devm_tegra_core_dev_init_opp_table()

2021-06-03T12:24:03+00:00

Use common devm_tegra_core_dev_init_opp_table() helper for the OPP table
initialization.

Tested-by: Paul Fertser  # PAZ00 T20
Tested-by: Nicolas Chauvet  # PAZ00 T20
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: Dmitry Osipenko 
Signed-off-by: Thierry Reding