[PATCH v3 1/3] staging: mt7621-mmc: Fix warning when reloading module with debug msgs enabled

From: George Hilliard
Date: Wed Mar 20 2019 - 18:44:01 EST


The kernel complained:

[ 510.277151] WARNING: CPU: 0 PID: 395 at fs/proc/generic.c:360 proc_register+0xf0/0x108
[ 510.292891] proc_dir_entry '/proc/msdc_debug' already registered

when doing a modprobe/rmmod/modprobe of this module if debug messages
are compiled in. Fix this by removing the proc entry when the module is
unloaded.

Signed-off-by: George Hilliard <thirtythreeforty@xxxxxxxxx>
---
v1: Initial attempt
v2: Rebased from v1
v3: Use #ifdef in header file, not implementation

drivers/staging/mt7621-mmc/dbg.c | 15 ++++++++++++---
drivers/staging/mt7621-mmc/dbg.h | 9 +++++++--
drivers/staging/mt7621-mmc/sd.c | 5 +++--
3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/mt7621-mmc/dbg.c b/drivers/staging/mt7621-mmc/dbg.c
index fda3ba38ba37..2310f3bcc16e 100644
--- a/drivers/staging/mt7621-mmc/dbg.c
+++ b/drivers/staging/mt7621-mmc/dbg.c
@@ -294,9 +294,18 @@ static const struct file_operations msdc_debug_fops = {
.release = single_release,
};

-void msdc_debug_proc_init(void)
+// Keep ahold of the proc entry we create so it can be freed during
+// module removal
+struct proc_dir_entry *msdc_debug_proc_entry;
+
+void __init msdc_debug_proc_init(void)
{
- proc_create("msdc_debug", 0660, NULL, &msdc_debug_fops);
+ msdc_debug_proc_entry = proc_create("msdc_debug", 0660,
+ NULL, &msdc_debug_fops);
+}
+
+void __exit msdc_debug_proc_deinit(void)
+{
+ proc_remove(msdc_debug_proc_entry);
}
-EXPORT_SYMBOL_GPL(msdc_debug_proc_init);
#endif
diff --git a/drivers/staging/mt7621-mmc/dbg.h b/drivers/staging/mt7621-mmc/dbg.h
index 2d447b2d92ae..b6a09876d7ae 100644
--- a/drivers/staging/mt7621-mmc/dbg.h
+++ b/drivers/staging/mt7621-mmc/dbg.h
@@ -92,8 +92,13 @@ enum msdc_dbg {
#define DBG_EVT_MASK (DBG_EVT_ALL)

extern unsigned int sd_debug_zone[4];
-#define TAG "msdc"
-void msdc_debug_proc_init(void);
+#ifdef MT6575_SD_DEBUG
+void __init msdc_debug_proc_init(void);
+void __exit msdc_debug_proc_deinit(void);
+#else
+static inline void msdc_debug_proc_init(void) {}
+static inline void msdc_debug_proc_deinit(void) {}
+#endif

u32 msdc_time_calc(u32 old_L32, u32 old_H32, u32 new_L32, u32 new_H32);
void msdc_performance(u32 opcode, u32 sizes, u32 bRx, u32 ticks);
diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index 40f23e200c7a..ff01872ab972 100644
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -1825,14 +1825,15 @@ static int __init mt_msdc_init(void)
return ret;
}

-#if defined(MT6575_SD_DEBUG)
msdc_debug_proc_init();
-#endif
+
return 0;
}

static void __exit mt_msdc_exit(void)
{
+ msdc_debug_proc_deinit();
+
platform_driver_unregister(&mt_msdc_driver);
}

--
2.21.0