linux/drivers/base, branch v5.7

driver core: Fix handling of SYNC_STATE_ONLY + STATELESS device links

2020-05-21T08:54:32Z

Commit 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link implementation") didn't completely fix STATELESS + SYNC_STATE_ONLY handling. What looks like an optimization in that commit is actually a bug that causes an if condition to always take the else path. This prevents reordering of devices in the dpm_list when a DL_FLAG_STATELESS device link is create on top of an existing DL_FLAG_SYNC_STATE_ONLY device link. Fixes: 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link implementation") Signed-off-by: Saravana Kannan Cc: stable Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20200520043626.181820-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Fix SYNC_STATE_ONLY device link implementation

2020-05-19T15:01:58Z

When SYNC_STATE_ONLY support was added in commit 05ef983e0d65 ("driver core: Add device link support for SYNC_STATE_ONLY flag"), device_link_add() incorrectly skipped adding the new SYNC_STATE_ONLY device link to the supplier's and consumer's "device link" list. This causes multiple issues: - The device link is lost forever from driver core if the caller didn't keep track of it (caller typically isn't expected to). This is a memory leak. - The device link is also never visible to any other code path after device_link_add() returns. If we fix the "device link" list handling, that exposes a bunch of issues. 1. The device link "status" state management code rightfully doesn't handle the case where a DL_FLAG_MANAGED device link exists between a supplier and consumer, but the consumer manages to probe successfully before the supplier. The addition of DL_FLAG_SYNC_STATE_ONLY links break this assumption. This causes device_links_driver_bound() to throw a warning when this happens. Since DL_FLAG_SYNC_STATE_ONLY device links are mainly used for creating proxy device links for child device dependencies and aren't useful once the consumer device probes successfully, this patch just deletes DL_FLAG_SYNC_STATE_ONLY device links once its consumer device probes. This way, we avoid the warning, free up some memory and avoid complicating the device links "status" state management code. 2. Creating a DL_FLAG_STATELESS device link between two devices that already have a DL_FLAG_SYNC_STATE_ONLY device link will result in the DL_FLAG_STATELESS flag not getting set correctly. This patch also fixes this. Lastly, this patch also fixes minor whitespace issues. Cc: stable@vger.kernel.org Fixes: 05ef983e0d65 ("driver core: Add device link support for SYNC_STATE_ONLY flag") Signed-off-by: Saravana Kannan Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20200519063000.128819-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires

2020-04-28T15:57:13Z

In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. This patch tries to fix the issue by creating a waitqueue for the driver_deferred_probe_timeout, and calling wait_event() to make sure driver_deferred_probe_timeout is zero in wait_for_device_probe() to make sure all the probing is finished. The downside to this solution is that kernel functionality that uses wait_for_device_probe(), will block until the driver_deferred_probe_timeout fires, regardless of if there is any missing dependencies. However, the previous patch reverts the default timeout value to zero, so this side-effect will only affect users who specify a driver_deferred_probe_timeout= value as a boot argument, where the additional delay would be beneficial to allow modules to load later during boot. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Cc: linux-pm@vger.kernel.org Reported-by: Yoshihiro Shimoda Tested-by: Geert Uytterhoeven Tested-by: Yoshihiro Shimoda Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-4-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman

driver core: Use dev_warn() instead of dev_WARN() for deferred_probe_timeout warnings

2020-04-28T15:57:13Z

In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") and following changes the logic was changes slightly so that if there is no driver to match whats found in the dtb, we wait the sepcified seconds for modules to be loaded by userland, and then timeout, where as previously we'd print "ignoring dependency for device, assuming no driver" and immediately return -ENODEV after initcall_done. However, in the timeout case (which previously existed but was practicaly un-used without a boot argument), the timeout message uses dev_WARN(). This means folks are now seeing a big backtrace in their boot logs if there a entry in their dts that doesn't have a driver. To fix this, lets use dev_warn(), instead of dev_WARN() to match the previous error path. Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Cc: linux-pm@vger.kernel.org Reviewed-by: Yoshihiro Shimoda Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-3-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman

driver core: Revert default driver_deferred_probe_timeout value to 0

2020-04-28T15:56:26Z

This patch addresses a regression in 5.7-rc1+ In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we both cleaned up the logic and also set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. Fixing that issue is possible, but could also introduce 30 second delays in bootups for users who don't have any missing dependencies, which is not ideal. So I think the best solution to avoid any regressions is to revert back to a default timeout value of zero, and allow systems that need to utilize the timeout in order for userland to load any modules that supply misisng dependencies in the dts to specify the timeout length via the exiting documented boot argument. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Reported-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Tested-by: Geert Uytterhoeven Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman

component: Silence bind error on -EPROBE_DEFER

2020-04-28T15:54:15Z

If a component fails to bind due to -EPROBE_DEFER we should not log an error as this is not a real failure. Fixes messages like: vc4-drm soc:gpu: failed to bind 3f902000.hdmi (ops vc4_hdmi_ops): -517 vc4-drm soc:gpu: master bind failed: -517 Signed-off-by: James Hilliard Link: https://lore.kernel.org/r/20200411190241.89404-1-james.hilliard1@gmail.com Signed-off-by: Greg Kroah-Hartman

driver core: Fix handling of fw_devlink=permissive

2020-04-28T15:54:13Z

When commit 8375e74f2bca ("driver core: Add fw_devlink kernel commandline option") added fw_devlink, it didn't implement "permissive" mode correctly. That commit got the device links flags correct to make sure unprobed suppliers don't block the probing of a consumer. However, if a consumer is waiting for mandatory suppliers to register, that could still block a consumer from probing. This commit fixes that by making sure in permissive mode, all suppliers to a consumer are treated as a optional suppliers. So, even if a consumer is waiting for suppliers to register and link itself (using the DL_FLAG_SYNC_STATE_ONLY flag) to the supplier, the consumer is never blocked from probing. Fixes: 8375e74f2bca ("driver core: Add fw_devlink kernel commandline option") Reported-by: Marek Szyprowski Signed-off-by: Saravana Kannan Tested-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200331022832.209618-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: platform: Initialize dma_parms for platform devices

2020-04-28T15:44:33Z

It's currently the platform driver's responsibility to initialize the pointer, dma_parms, for its corresponding struct device. The benefit with this approach allows us to avoid the initialization and to not waste memory for the struct device_dma_parameters, as this can be decided on a case by case basis. However, it has turned out that this approach is not very practical. Not only does it lead to open coding, but also to real errors. In principle callers of dma_set_max_seg_size() doesn't check the error code, but just assumes it succeeds. For these reasons, let's do the initialization from the common platform bus at the device registration point. This also follows the way the PCI devices are being managed, see pci_device_add(). Suggested-by: Christoph Hellwig Cc: Tested-by: Haibo Chen Reviewed-by: Arnd Bergmann Signed-off-by: Ulf Hansson Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200422100954.31211-1-ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2020-04-26T18:04:15Z

Pull driver core fixes from Greg KH: "Here are some small firmware/driver core/debugfs fixes for 5.7-rc3. The debugfs change is now possible as now the last users of debugfs_create_u32() have been fixed up in the different trees that got merged into 5.7-rc1, and I don't want it creeping back in. The firmware changes did cause a regression in linux-next, so the final patch here reverts part of that, re-exporting the symbol to resolve that issue. All of these patches, with the exception of the final one, have been in linux-next with only that one reported issue" * tag 'driver-core-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: firmware_loader: revert removal of the fw_fallback_config export debugfs: remove return value of debugfs_create_u32() firmware_loader: remove unused exports firmware: imx: fix compile-testing

firmware_loader: revert removal of the fw_fallback_config export

2020-04-26T08:42:15Z

Christoph's patch removed two unsused exported symbols, however, one symbol is used by the firmware_loader itself. If CONFIG_FW_LOADER=m so the firmware_loader is modular but CONFIG_FW_LOADER_USER_HELPER=y we fail the build at mostpost. ERROR: modpost: "fw_fallback_config" [drivers/base/firmware_loader/firmware_class.ko] undefined! This happens because the variable fw_fallback_config is built into the kernel if CONFIG_FW_LOADER_USER_HELPER=y always, so we need to grant access to the firmware loader module by exporting it. Revert only one hunk from his patch. Fixes: 739604734bd8 ("firmware_loader: remove unused exports") Reported-by: Randy Dunlap Signed-off-by: Luis Chamberlain Link: https://lore.kernel.org/r/20200424184916.22843-1-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman