ath6kl: silence "invalid rate" warning

For some reason firmware is sending invalid rates when we try to
query current bitrate from ath6kl_get_station() and a warning is issued:

[ 3810.415720] ath6kl: invalid rate: 1935633515
[ 3811.105493] ath6kl: invalid rate: 1935633515
[ 3811.556063] ath6kl: invalid rate: 1935633515

As the warning happens way too often, convert the warning to a debug
message once we have a proper fix. But to make it easy to follow
how often the problem appears, add a debugfs to print
various statistics about workarounds and make this issue the first WAR.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

4 files changed, 64 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index c84f53d6523b..8d9fbd4a62b7 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -1365,7 +1365,9 @@ static int ath6kl_get_station(struct wiphy *wiphy, struct net_device *dev,
                 sinfo->txrate.flags |= RATE_INFO_FLAGS_40_MHZ_WIDTH;
                 sinfo->txrate.flags |= RATE_INFO_FLAGS_MCS;
         } else {
-                ath6kl_warn("invalid rate: %d\n", rate);
+                ath6kl_dbg(ATH6KL_DBG_WLAN_CFG,
+                           "invalid rate from stats: %d\n", rate);
+                ath6kl_debug_war(ar, ATH6KL_WAR_INVALID_RATE);
                 return 0;
         }
 
diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h
index 9ecf22bd4fc9..6d8a4845baaf 100644
--- a/drivers/net/wireless/ath/ath6kl/core.h
+++ b/drivers/net/wireless/ath/ath6kl/core.h
@@ -525,6 +525,10 @@ struct ath6kl {
                 unsigned int dbgfs_diag_reg;
                 u32 diag_reg_addr_wr;
                 u32 diag_reg_val_wr;
+
+                struct {
+                        unsigned int invalid_rate;
+                } war_stats;
         } debug;
 #endif /* CONFIG_ATH6KL_DEBUG */
 };
diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c
index 4fc83ccbf8bd..5237369cd521 100644
--- a/drivers/net/wireless/ath/ath6kl/debug.c
+++ b/drivers/net/wireless/ath/ath6kl/debug.c
@@ -192,6 +192,51 @@ static int ath6kl_debugfs_open(struct inode *inode, struct file *file)
         return 0;
 }
 
+void ath6kl_debug_war(struct ath6kl *ar, enum ath6kl_war war)
+{
+        switch (war) {
+        case ATH6KL_WAR_INVALID_RATE:
+                ar->debug.war_stats.invalid_rate++;
+                break;
+        }
+}
+
+static ssize_t read_file_war_stats(struct file *file, char __user *user_buf,
+                                   size_t count, loff_t *ppos)
+{
+        struct ath6kl *ar = file->private_data;
+        char *buf;
+        unsigned int len = 0, buf_len = 1500;
+        ssize_t ret_cnt;
+
+        buf = kzalloc(buf_len, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        len += scnprintf(buf + len, buf_len - len, "\n");
+        len += scnprintf(buf + len, buf_len - len, "%25s\n",
+                         "Workaround stats");
+        len += scnprintf(buf + len, buf_len - len, "%25s\n\n",
+                         "=================");
+        len += scnprintf(buf + len, buf_len - len, "%20s %10u\n",
+                         "Invalid rates", ar->debug.war_stats.invalid_rate);
+
+        if (WARN_ON(len > buf_len))
+                len = buf_len;
+
+        ret_cnt = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+
+        kfree(buf);
+        return ret_cnt;
+}
+
+static const struct file_operations fops_war_stats = {
+        .read = read_file_war_stats,
+        .open = ath6kl_debugfs_open,
+        .owner = THIS_MODULE,
+        .llseek = default_llseek,
+};
+
 static void ath6kl_debug_fwlog_add(struct ath6kl *ar, const void *buf,
                                    size_t buf_len)
 {
@@ -873,6 +918,9 @@ int ath6kl_debug_init(struct ath6kl *ar)
         debugfs_create_file("reg_write", S_IRUSR | S_IWUSR,
                             ar->debugfs_phy, ar, &fops_diag_reg_write);
 
+        debugfs_create_file("war_stats", S_IRUSR, ar->debugfs_phy, ar,
+                            &fops_war_stats);
+
         return 0;
 }
 
diff --git a/drivers/net/wireless/ath/ath6kl/debug.h b/drivers/net/wireless/ath/ath6kl/debug.h
index 89bf8e1138a3..91f4bc35f968 100644
--- a/drivers/net/wireless/ath/ath6kl/debug.h
+++ b/drivers/net/wireless/ath/ath6kl/debug.h
@@ -52,6 +52,10 @@ extern int ath6kl_printk(const char *level, const char *fmt, ...)
 
 #define AR_DBG_LVL_CHECK(mask)  (debug_mask & mask)
 
+enum ath6kl_war {
+        ATH6KL_WAR_INVALID_RATE,
+};
+
 #ifdef CONFIG_ATH6KL_DEBUG
 #define ath6kl_dbg(mask, fmt, ...)                                      \
         ({                                                              \
@@ -79,6 +83,7 @@ void ath6kl_dump_registers(struct ath6kl_device *dev,
                            struct ath6kl_irq_enable_reg *irq_en_reg);
 void dump_cred_dist_stats(struct htc_target *target);
 void ath6kl_debug_fwlog_event(struct ath6kl *ar, const void *buf, size_t len);
+void ath6kl_debug_war(struct ath6kl *ar, enum ath6kl_war war);
 int ath6kl_debug_init(struct ath6kl *ar);
 void ath6kl_debug_cleanup(struct ath6kl *ar);
 
@@ -110,6 +115,10 @@ static inline void ath6kl_debug_fwlog_event(struct ath6kl *ar,
 {
 }
 
+static inline void ath6kl_debug_war(struct ath6kl *ar, enum ath6kl_war war)
+{
+}
+
 static inline int ath6kl_debug_init(struct ath6kl *ar)
 {
         return 0;