[PATCH v2 14/16] soundwire: Use acpi_dev_for_each_child()
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children.
This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing).
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Tested-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com ---
v1 -> v2: * Make sure errors are not lost (Pierre-Louis). * Add R-by and T-by from Pierre-Louis.
--- drivers/soundwire/slave.c | 117 ++++++++++++++++++++++++++-------------------- 1 file changed, 67 insertions(+), 50 deletions(-)
Index: linux-pm/drivers/soundwire/slave.c =================================================================== --- linux-pm.orig/drivers/soundwire/slave.c +++ linux-pm/drivers/soundwire/slave.c @@ -127,6 +127,71 @@ static bool find_slave(struct sdw_bus *b return true; }
+struct sdw_acpi_child_walk_data { + struct sdw_bus *bus; + struct acpi_device *adev; + struct sdw_slave_id id; + bool ignore_unique_id; +}; + +static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data) +{ + struct sdw_acpi_child_walk_data *cwd = data; + struct sdw_bus *bus = cwd->bus; + struct sdw_slave_id id; + + if (adev == cwd->adev) + return 0; + + if (!find_slave(bus, adev, &id)) + return 0; + + if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id || + cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id) + return 0; + + if (cwd->id.unique_id != id.unique_id) { + dev_dbg(bus->dev, + "Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n", + cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, + cwd->id.part_id); + cwd->ignore_unique_id = false; + return 0; + } + + dev_err(bus->dev, + "Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n", + cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id); + return -ENODEV; +} + +static int sdw_acpi_find_one(struct acpi_device *adev, void *data) +{ + struct sdw_bus *bus = data; + struct sdw_acpi_child_walk_data cwd = { + .bus = bus, + .adev = adev, + .ignore_unique_id = true, + }; + int ret; + + if (!find_slave(bus, adev, &cwd.id)) + return 0; + + /* Brute-force O(N^2) search for duplicates. */ + ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev), + sdw_acpi_check_duplicate, &cwd); + if (ret) + return ret; + + if (cwd.ignore_unique_id) + cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID; + + /* Ignore errors and continue. */ + sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev)); + return 0; +} + /* * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node * @bus: SDW bus instance @@ -135,8 +200,7 @@ static bool find_slave(struct sdw_bus *b */ int sdw_acpi_find_slaves(struct sdw_bus *bus) { - struct acpi_device *adev, *parent; - struct acpi_device *adev2, *parent2; + struct acpi_device *parent;
parent = ACPI_COMPANION(bus->dev); if (!parent) { @@ -144,54 +208,7 @@ int sdw_acpi_find_slaves(struct sdw_bus return -ENODEV; }
- list_for_each_entry(adev, &parent->children, node) { - struct sdw_slave_id id; - struct sdw_slave_id id2; - bool ignore_unique_id = true; - - if (!find_slave(bus, adev, &id)) - continue; - - /* brute-force O(N^2) search for duplicates */ - parent2 = parent; - list_for_each_entry(adev2, &parent2->children, node) { - - if (adev == adev2) - continue; - - if (!find_slave(bus, adev2, &id2)) - continue; - - if (id.sdw_version != id2.sdw_version || - id.mfg_id != id2.mfg_id || - id.part_id != id2.part_id || - id.class_id != id2.class_id) - continue; - - if (id.unique_id != id2.unique_id) { - dev_dbg(bus->dev, - "Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n", - id.unique_id, id2.unique_id, id.mfg_id, id.part_id); - ignore_unique_id = false; - } else { - dev_err(bus->dev, - "Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n", - id.unique_id, id2.unique_id, id.mfg_id, id.part_id); - return -ENODEV; - } - } - - if (ignore_unique_id) - id.unique_id = SDW_IGNORED_UNIQUE_ID; - - /* - * don't error check for sdw_slave_add as we want to continue - * adding Slaves - */ - sdw_slave_add(bus, &id, acpi_fwnode_handle(adev)); - } - - return 0; + return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus); }
#endif
On 13-06-22, 20:35, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children.
This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing).
Applied, thanks
On Thu, Jun 23, 2022 at 10:10 AM Vinod Koul vkoul@kernel.org wrote:
On 13-06-22, 20:35, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children.
This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing).
Applied, thanks
Thanks, but the export of acpi_dev_for_each_child() is being added by one of the previous patches in the series, so this one will not compile without the rest of the series in the modular case.
Is this not a problem?
On 23-06-22, 14:29, Rafael J. Wysocki wrote:
On Thu, Jun 23, 2022 at 10:10 AM Vinod Koul vkoul@kernel.org wrote:
On 13-06-22, 20:35, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children.
This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing).
Applied, thanks
Thanks, but the export of acpi_dev_for_each_child() is being added by one of the previous patches in the series, so this one will not compile without the rest of the series in the modular case.
Aha, I checked the symbol exists and my test build passed!
Is this not a problem?
Yes indeed, so can you give a tag for that and or would you like to taje this thru ACPI tree, in that case
Acked-By: Vinod Koul vkoul@kernel.org
BR
On Thu, Jun 23, 2022 at 2:41 PM Vinod Koul vkoul@kernel.org wrote:
On 23-06-22, 14:29, Rafael J. Wysocki wrote:
On Thu, Jun 23, 2022 at 10:10 AM Vinod Koul vkoul@kernel.org wrote:
On 13-06-22, 20:35, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children.
This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing).
Applied, thanks
Thanks, but the export of acpi_dev_for_each_child() is being added by one of the previous patches in the series, so this one will not compile without the rest of the series in the modular case.
Aha, I checked the symbol exists and my test build passed!
Is this not a problem?
Yes indeed, so can you give a tag for that and or would you like to taje this thru ACPI tree, in that case
I'll take it.
Acked-By: Vinod Koul vkoul@kernel.org
Thank you!
participants (3)
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Rafael J. Wysocki -
Rafael J. Wysocki -
Vinod Koul