kernel.git/drivers/gpu/drm/tegra/sor.c, branch linux-5.14.y

drm/tegra: sor: Fix AUX device reference leak

2021-05-27T18:11:13Z

In the case where the AUX provides an I2C-over-AUX DDC channel, a reference is taken on the AUX parent device of the DDC channel rather than the DDC channel like it would be for regular I2C controllers. To make sure the correct reference is dropped, move the unreferencing code into the SOR driver and make sure not to drop the I2C adapter reference in that case. Signed-off-by: Thierry Reding

drm/tegra: Get ref for DP AUX channel, not its ddc adapter

2021-05-27T18:11:07Z

While we're taking a reference of the DDC adapter for a DP AUX channel in tegra_sor_probe() because we're going to be using that adapter with the SOR, now that we've moved where AUX registration happens the actual device structure for the DDC adapter isn't initialized yet. Which means that we can't really take a reference from it to try to keep it around anymore. This should be fine though, because we can just take a reference of its parent instead. v2: * Avoid calling i2c_put_adapter() in tegra_output_remove() for eDP/DP cases Signed-off-by: Lyude Paul Fixes: 39c17ae60ea9 ("drm/tegra: Don't register DP AUX channels before connectors") Cc: Lyude Paul Cc: Thierry Reding Cc: Jonathan Hunter Cc: dri-devel@lists.freedesktop.org Cc: linux-tegra@vger.kernel.org Signed-off-by: Thierry Reding

drm/tegra: sor: Fully initialize SOR before registration

2021-05-17T10:31:05Z

Before registering the SOR host1x client, make sure that it is fully initialized. This avoids a potential race condition between the SOR's probe and the host1x device initialization in cases where the SOR is the final sub-device to register to a host1x instance. Reported-by: Jonathan Hunter Signed-off-by: Thierry Reding Tested-by: Jon Hunter Signed-off-by: Thierry Reding

drm/tegra: sor: Do not leak runtime PM reference

2021-05-17T10:31:05Z

It's theoretically possible for the runtime PM reference to leak if the code fails anywhere between the pm_runtime_resume_and_get() and pm_runtime_put() calls, so make sure to release the runtime PM reference in that case. Practically this will never happen because none of the functions will fail on Tegra, but it's better for the code to be pedantic in case these assumptions will ever become wrong. Signed-off-by: Pavel Machek (CIP) [treding@nvidia.com: add commit message] Signed-off-by: Thierry Reding

drm/tegra: sor: Grab runtime PM reference across reset

2021-03-30T17:51:39Z

The SOR resets are exclusively shared with the SOR power domain. This means that exclusive access can only be granted temporarily and in order for that to work, a rigorous sequence must be observed. To ensure that a single consumer gets exclusive access to a reset, each consumer must implement a rigorous protocol using the reset_control_acquire() and reset_control_release() functions. However, these functions alone don't provide any guarantees at the system level. Drivers need to ensure that the only a single consumer has access to the reset at the same time. In order for the SOR to be able to exclusively access its reset, it must therefore ensure that the SOR power domain is not powered off by holding on to a runtime PM reference to that power domain across the reset assert/deassert operation. This used to work fine by accident, but was revealed when recently more devices started to rely on the SOR power domain. Fixes: 11c632e1cfd3 ("drm/tegra: sor: Implement acquire/release for reset") Reported-by: Jonathan Hunter Signed-off-by: Thierry Reding

drm/tegra: Fix reference leak when pm_runtime_get_sync() fails

2021-01-15T16:24:51Z

The PM reference count is not expected to be incremented on return in these Tegra functions. However, pm_runtime_get_sync() will increment the PM reference count even on failure. Forgetting to put the reference again will result in a leak. Replace it with pm_runtime_resume_and_get() to keep the usage counter balanced. Fixes: fd67e9c6ed5a ("drm/tegra: Do not implement runtime PM") Reported-by: Hulk Robot Signed-off-by: Qinglang Miao Signed-off-by: Thierry Reding

drm/tegra: sor: Disable clocks on error in tegra_sor_init()

2020-11-26T17:44:48Z

Fix the missing clk_disable_unprepare() before return from tegra_sor_init() in the error handling case. Signed-off-by: Qinglang Miao Signed-off-by: Thierry Reding

drm/tegra: sor: Ensure regulators are disabled on teardown

2020-11-10T17:37:23Z

The Tegra SOR driver uses the devm infrastructure to request regulators, but enables them without registering them with the infrastructure. This results in the following splat if probing fails for any odd resaon (such as dependencies not being available): [ 8.974187] tegra-sor 15580000.sor: cannot get HDMI supply: -517 [ 9.414403] tegra-sor 15580000.sor: failed to probe HDMI: -517 [ 9.421240] ------------[ cut here ]------------ [ 9.425879] WARNING: CPU: 1 PID: 164 at drivers/regulator/core.c:2089 _regulator_put.part.0+0x16c/0x174 [ 9.435259] Modules linked in: tegra_drm(E+) cec(E) ahci_tegra(E) drm_kms_helper(E) drm(E) libahci_platform(E) libahci(E) max77620_regulator(E) xhci_tegra(E+) sdhci_tegra(E) xhci_hcd(E) libata(E) sdhci_pltfm(E) cqhci(E) fixed(E) usbcore(E) scsi_mod(E) sdhci(E) host1x(E) [ 9.459211] CPU: 1 PID: 164 Comm: systemd-udevd Tainted: G S D W E 5.9.0-rc7-00298-gf6337624c4fe #1980 [ 9.469285] Hardware name: NVIDIA Jetson TX2 Developer Kit (DT) [ 9.475202] pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--) [ 9.480784] pc : _regulator_put.part.0+0x16c/0x174 [ 9.485581] lr : regulator_put+0x44/0x60 [ 9.489501] sp : ffffffc011d837b0 [ 9.492814] x29: ffffffc011d837b0 x28: ffffff81dd085900 [ 9.498141] x27: ffffff81de1c8ec0 x26: ffffff81de1c8c10 [ 9.503464] x25: ffffff81dd085800 x24: ffffffc008f2c6b0 [ 9.508790] x23: ffffffc0117373f0 x22: 0000000000000005 [ 9.514101] x21: ffffff81dd085900 x20: ffffffc01172b098 [ 9.515822] ata1: SATA link down (SStatus 0 SControl 300) [ 9.519426] x19: ffffff81dd085100 x18: 0000000000000030 [ 9.530122] x17: 0000000000000000 x16: 0000000000000000 [ 9.535453] x15: 0000000000000000 x14: 000000000000038f [ 9.540777] x13: 0000000000000003 x12: 0000000000000040 [ 9.546105] x11: ffffff81eb800000 x10: 0000000000000ae0 [ 9.551417] x9 : ffffffc0106fea24 x8 : ffffff81de83e6c0 [ 9.556728] x7 : 0000000000000018 x6 : 00000000000003c3 [ 9.562064] x5 : 0000000000005660 x4 : 0000000000000000 [ 9.567392] x3 : ffffffc01172b388 x2 : ffffff81de83db80 [ 9.572702] x1 : 0000000000000000 x0 : 0000000000000001 [ 9.578034] Call trace: [ 9.580494] _regulator_put.part.0+0x16c/0x174 [ 9.584940] regulator_put+0x44/0x60 [ 9.588522] devm_regulator_release+0x20/0x2c [ 9.592885] release_nodes+0x1c8/0x2c0 [ 9.596636] devres_release_all+0x44/0x6c [ 9.600649] really_probe+0x1ec/0x504 [ 9.604316] driver_probe_device+0x100/0x170 [ 9.608589] device_driver_attach+0xcc/0xd4 [ 9.612774] __driver_attach+0xb0/0x17c [ 9.616614] bus_for_each_dev+0x7c/0xd4 [ 9.620450] driver_attach+0x30/0x3c [ 9.624027] bus_add_driver+0x154/0x250 [ 9.627867] driver_register+0x84/0x140 [ 9.631719] __platform_register_drivers+0xa0/0x180 [ 9.636660] host1x_drm_init+0x60/0x1000 [tegra_drm] [ 9.641629] do_one_initcall+0x54/0x2d0 [ 9.645490] do_init_module+0x68/0x29c [ 9.649244] load_module+0x2178/0x26c0 [ 9.652997] __do_sys_finit_module+0xb0/0x120 [ 9.657356] __arm64_sys_finit_module+0x2c/0x40 [ 9.661902] el0_svc_common.constprop.0+0x80/0x240 [ 9.666701] do_el0_svc+0x30/0xa0 [ 9.670022] el0_svc+0x18/0x50 [ 9.673081] el0_sync_handler+0x90/0x318 [ 9.677006] el0_sync+0x158/0x180 [ 9.680324] ---[ end trace 90f6c89d62d85ff6 ]--- Instead, let's register a callback that will disable the regulators on teardown. This allows for the removal of the .remove callbacks, which are not needed anymore. Signed-off-by: Marc Zyngier Signed-off-by: Thierry Reding

drm/tegra: sor: Don't warn on probe deferral

2020-11-09T13:32:45Z

Deferred probe is an expected return value for tegra_output_probe(). Given that the driver deals with it properly, there's no need to output a warning that may potentially confuse users. Signed-off-by: Jon Hunter Signed-off-by: Thierry Reding

drm/tegra: Properly reference count the DDC I2C adapter

2020-09-17T10:27:11Z

Use the of_get_i2c_adapter_by_node(), which is similar to the existing call to of_find_i2c_adapter_by_node() except that it also takes a reference to the owner module of the I2C adapter. In order to properly balance this out, call i2c_put_adapter() to release the reference to the I2C adapter and its owner module. For the special case where the DDC comes from the DPAUX, care must be taken to perform the same steps (i.e. get_device() and module_get()) so that the reference counts are all balanced. Signed-off-by: Thierry Reding