| Message ID | 1462210075-5320-1-git-send-email-javier@osg.samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Monday 02 May 2016 13:27:54 Javier Martinez Canillas wrote: > 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(): > Better assign the pointer to NULL in case of a non-fatal error return code. That way, the reader doesn't have to wonder why you have the IS_ERR_OR_NULL() check here. Arnd
Hello Arnd, Thanks for your feedback. On 05/02/2016 02:41 PM, Arnd Bergmann wrote: > On Monday 02 May 2016 13:27:54 Javier Martinez Canillas wrote: >> 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(): >> > > Better assign the pointer to NULL in case of a non-fatal error > return code. That way, the reader doesn't have to wonder why you > have the IS_ERR_OR_NULL() check here. > Ok, I'll re-spin the patch doing that instead. > Arnd > Best regards,
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c index 5f97a3398c11..d011f30be265 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c @@ -85,7 +85,7 @@ err_g_ip_clk: void s5p_mfc_final_pm(struct s5p_mfc_dev *dev) { if (dev->variant->version != MFC_VERSION_V6 && - pm->clock) { + !IS_ERR_OR_NULL(pm->clock)) { clk_disable_unprepare(pm->clock); clk_put(pm->clock); }
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) So check if the pointer is not an errno value before calling clk_put(). Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> --- drivers/media/platform/s5p-mfc/s5p_mfc_pm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)