This is a note to let you know that I've just added the patch titled staging: board: Fix uninitialized spinlock when attaching genpd to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: staging-board-fix-uninitialized-spinlock-when-attach.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c28cfad8899b93dba6c5f40793c4087a157f74a4 Author: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Date: Wed Jul 14 12:13:46 2021 +0200 staging: board: Fix uninitialized spinlock when attaching genpd [ Upstream commit df00609821bf17f50a75a446266d19adb8339d84 ] On Armadillo-800-EVA with CONFIG_DEBUG_SPINLOCK=y: BUG: spinlock bad magic on CPU#0, swapper/1 lock: lcdc0_device+0x10c/0x308, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 1 Comm: swapper Not tainted 5.11.0-rc5-armadillo-00036-gbbca04be7a80-dirty #287 Hardware name: Generic R8A7740 (Flattened Device Tree) [<c010c3c8>] (unwind_backtrace) from [<c010a49c>] (show_stack+0x10/0x14) [<c010a49c>] (show_stack) from [<c0159534>] (do_raw_spin_lock+0x20/0x94) [<c0159534>] (do_raw_spin_lock) from [<c040858c>] (dev_pm_get_subsys_data+0x8c/0x11c) [<c040858c>] (dev_pm_get_subsys_data) from [<c05fbcac>] (genpd_add_device+0x78/0x2b8) [<c05fbcac>] (genpd_add_device) from [<c0412db4>] (of_genpd_add_device+0x34/0x4c) [<c0412db4>] (of_genpd_add_device) from [<c0a1ea74>] (board_staging_register_device+0x11c/0x148) [<c0a1ea74>] (board_staging_register_device) from [<c0a1eac4>] (board_staging_register_devices+0x24/0x28) of_genpd_add_device() is called before platform_device_register(), as it needs to attach the genpd before the device is probed. But the spinlock is only initialized when the device is registered. Fix this by open-coding the spinlock initialization, cfr. device_pm_init_common() in the internal drivers/base code, and in the SuperH early platform code. Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Link: https://lore.kernel.org/r/57783ece7ddae55f2bda2f59f452180bff744ea0.1626257398.git.geert+renesas@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/staging/board/board.c b/drivers/staging/board/board.c index cb6feb34dd40..f980af037345 100644 --- a/drivers/staging/board/board.c +++ b/drivers/staging/board/board.c @@ -136,6 +136,7 @@ int __init board_staging_register_clock(const struct board_staging_clk *bsc) static int board_staging_add_dev_domain(struct platform_device *pdev, const char *domain) { + struct device *dev = &pdev->dev; struct of_phandle_args pd_args; struct device_node *np; @@ -148,7 +149,11 @@ static int board_staging_add_dev_domain(struct platform_device *pdev, pd_args.np = np; pd_args.args_count = 0; - return of_genpd_add_device(&pd_args, &pdev->dev); + /* Initialization similar to device_pm_init_common() */ + spin_lock_init(&dev->power.lock); + dev->power.early_init = true; + + return of_genpd_add_device(&pd_args, dev); } #else static inline int board_staging_add_dev_domain(struct platform_device *pdev,