Failing to get the struct s5p_mfc_pm .clock is a non-fatal error so the clock field can have a errno pointer value. But s5p_mfc_final_pm() only checks if .clock is not NULL before attempting to unprepare and put it. This leads to the following warning in clk_put() due s5p_mfc_final_pm(): WARNING: CPU: 3 PID: 1023 at drivers/clk/clk.c:2814 s5p_mfc_final_pm+0x48/0x74 [s5p_mfc] CPU: 3 PID: 1023 Comm: rmmod Tainted: G W 4.6.0-rc6-next-20160502-00005-g5a15a49106bc #9 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c010e1bc>] (unwind_backtrace) from [<c010af28>] (show_stack+0x10/0x14) [<c010af28>] (show_stack) from [<c032485c>] (dump_stack+0x88/0x9c) [<c032485c>] (dump_stack) from [<c011b8e8>] (__warn+0xe8/0x100) [<c011b8e8>] (__warn) from [<c011b9b0>] (warn_slowpath_null+0x20/0x28) [<c011b9b0>] (warn_slowpath_null) from [<bf16004c>] (s5p_mfc_final_pm+0x48/0x74 [s5p_mfc]) [<bf16004c>] (s5p_mfc_final_pm [s5p_mfc]) from [<bf157414>] (s5p_mfc_remove+0x8c/0x94 [s5p_mfc]) [<bf157414>] (s5p_mfc_remove [s5p_mfc]) from [<c03fe1f8>] (platform_drv_remove+0x24/0x3c) [<c03fe1f8>] (platform_drv_remove) from [<c03fcc70>] (__device_release_driver+0x84/0x110) [<c03fcc70>] (__device_release_driver) from [<c03fcdd8>] (driver_detach+0xac/0xb0) [<c03fcdd8>] (driver_detach) from [<c03fbff8>] (bus_remove_driver+0x4c/0xa0) [<c03fbff8>] (bus_remove_driver) from [<c01886a8>] (SyS_delete_module+0x174/0x1b8) [<c01886a8>] (SyS_delete_module) from [<c01078c0>] (ret_fast_syscall+0x0/0x3c) Assign the pointer to NULL in case of a lookup failure to fix the issue. Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> --- Changes in v2: - Set the clock pointer to NULL instead of checking for !IS_ERR_OR_NULL(). Suggested by Arnd Bergmann. drivers/media/platform/s5p-mfc/s5p_mfc_pm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c index 5f97a3398c11..9f7522104333 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c @@ -54,6 +54,7 @@ int s5p_mfc_init_pm(struct s5p_mfc_dev *dev) pm->clock = clk_get(&dev->plat_dev->dev, MFC_SCLK_NAME); if (IS_ERR(pm->clock)) { mfc_info("Failed to get MFC special clock control\n"); + pm->clock = NULL; } else { clk_set_rate(pm->clock, MFC_SCLK_RATE); ret = clk_prepare_enable(pm->clock); -- 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html