ath10k: cache calibration data when the core is stopped

Commit 0b8e3c4ca29f ("ath10k: move cal data len to hw_params") broke retrieving
the calibration data from cal_data debugfs file. The length of file was always
zero. The reason is:

    static ssize_t ath10k_debug_cal_data_read(struct file *file,
                                          char __user *user_buf,
                                          size_t count, loff_t *ppos)
    {
        struct ath10k *ar = file->private_data;
        void *buf = file->private_data;

This is obviously bogus, private_data cannot contain both struct ath10k and the
buffer. Fix it by caching calibration data to ar->debug.cal_data. This also
allows it to be accessed when the device is not active (interface is down).

The cal_data buffer is fixed size because during the first firmware probe we
don't yet know what will be the lenght of the calibration data. It was simplest
just to use a fixed length. There's a WARN_ON() in
ath10k_debug_cal_data_fetch() if the buffer is too small.

Tested with qca988x and firmware 10.2.4.70.56.

Reported-by: Nikolay Martynov <mar.kolya@gmail.com>
Fixes: 0b8e3c4ca29f ("ath10k: move cal data len to hw_params")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Marty Faltesek <mfaltesek@google.com>
[kvalo@qca.qualcomm.com: improve commit log and minor other changes]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index dda49af..521f1c5 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -450,6 +450,7 @@ struct ath10k_debug {
        u32 pktlog_filter;
        u32 reg_addr;
        u32 nf_cal_period;
+       void *cal_data;
 
        struct ath10k_fw_crash_data *fw_crash_data;
 };

diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index 832da6e..82a4c67 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -30,6 +30,8 @@
 /* ms */
 #define ATH10K_DEBUG_HTT_STATS_INTERVAL 1000
 
+#define ATH10K_DEBUG_CAL_DATA_LEN 12064
+
 #define ATH10K_FW_CRASH_DUMP_VERSION 1
 
 /**
@@ -1451,56 +1453,51 @@ static const struct file_operations fops_fw_dbglog = {
        .llseek = default_llseek,
 };
 
-static int ath10k_debug_cal_data_open(struct inode *inode, struct file *file)
+static int ath10k_debug_cal_data_fetch(struct ath10k *ar)
 {
-       struct ath10k *ar = inode->i_private;
-       void *buf;
        u32 hi_addr;
        __le32 addr;
        int ret;
 
-       mutex_lock(&ar->conf_mutex);
-
-       if (ar->state != ATH10K_STATE_ON &&
-           ar->state != ATH10K_STATE_UTF) {
-               ret = -ENETDOWN;
-               goto err;
-       }
+       lockdep_assert_held(&ar->conf_mutex);
 
-       buf = vmalloc(ar->hw_params.cal_data_len);
-       if (!buf) {
-               ret = -ENOMEM;
-               goto err;
-       }
+       if (WARN_ON(ar->hw_params.cal_data_len > ATH10K_DEBUG_CAL_DATA_LEN))
+               return -EINVAL;
 
        hi_addr = host_interest_item_address(HI_ITEM(hi_board_data));
 
        ret = ath10k_hif_diag_read(ar, hi_addr, &addr, sizeof(addr));
        if (ret) {
-               ath10k_warn(ar, "failed to read hi_board_data address: %d\n", ret);
-               goto err_vfree;
+               ath10k_warn(ar, "failed to read hi_board_data address: %d\n",
+                           ret);
+               return ret;
        }
 
-       ret = ath10k_hif_diag_read(ar, le32_to_cpu(addr), buf,
+       ret = ath10k_hif_diag_read(ar, le32_to_cpu(addr), ar->debug.cal_data,
                                   ar->hw_params.cal_data_len);
        if (ret) {
                ath10k_warn(ar, "failed to read calibration data: %d\n", ret);
-               goto err_vfree;
+               return ret;
        }
 
-       file->private_data = buf;
+       return 0;
+}
 
-       mutex_unlock(&ar->conf_mutex);
+static int ath10k_debug_cal_data_open(struct inode *inode, struct file *file)
+{
+       struct ath10k *ar = inode->i_private;
 
-       return 0;
+       mutex_lock(&ar->conf_mutex);
 
-err_vfree:
-       vfree(buf);
+       if (ar->state == ATH10K_STATE_ON ||
+           ar->state == ATH10K_STATE_UTF) {
+               ath10k_debug_cal_data_fetch(ar);
+       }
 
-err:
+       file->private_data = ar;
        mutex_unlock(&ar->conf_mutex);
 
-       return ret;
+       return 0;
 }
 
 static ssize_t ath10k_debug_cal_data_read(struct file *file,
@@ -1508,18 +1505,16 @@ static ssize_t ath10k_debug_cal_data_read(struct file *file,
                                          size_t count, loff_t *ppos)
 {
        struct ath10k *ar = file->private_data;
-       void *buf = file->private_data;
 
-       return simple_read_from_buffer(user_buf, count, ppos,
-                                      buf, ar->hw_params.cal_data_len);
-}
+       mutex_lock(&ar->conf_mutex);
 
-static int ath10k_debug_cal_data_release(struct inode *inode,
-                                        struct file *file)
-{
-       vfree(file->private_data);
+       count = simple_read_from_buffer(user_buf, count, ppos,
+                                       ar->debug.cal_data,
+                                       ar->hw_params.cal_data_len);
 
-       return 0;
+       mutex_unlock(&ar->conf_mutex);
+
+       return count;
 }
 
 static ssize_t ath10k_write_ani_enable(struct file *file,
@@ -1580,7 +1575,6 @@ static const struct file_operations fops_ani_enable = {
 static const struct file_operations fops_cal_data = {
        .open = ath10k_debug_cal_data_open,
        .read = ath10k_debug_cal_data_read,
-       .release = ath10k_debug_cal_data_release,
        .owner = THIS_MODULE,
        .llseek = default_llseek,
 };
@@ -1932,6 +1926,8 @@ void ath10k_debug_stop(struct ath10k *ar)
 {
        lockdep_assert_held(&ar->conf_mutex);
 
+       ath10k_debug_cal_data_fetch(ar);
+
        /* Must not use _sync to avoid deadlock, we do that in
         * ath10k_debug_destroy(). The check for htt_stats_mask is to avoid
         * warning from del_timer(). */
@@ -2344,6 +2340,10 @@ int ath10k_debug_create(struct ath10k *ar)
        if (!ar->debug.fw_crash_data)
                return -ENOMEM;
 
+       ar->debug.cal_data = vzalloc(ATH10K_DEBUG_CAL_DATA_LEN);
+       if (!ar->debug.cal_data)
+               return -ENOMEM;
+
        INIT_LIST_HEAD(&ar->debug.fw_stats.pdevs);
        INIT_LIST_HEAD(&ar->debug.fw_stats.vdevs);
        INIT_LIST_HEAD(&ar->debug.fw_stats.peers);
@@ -2357,6 +2357,9 @@ void ath10k_debug_destroy(struct ath10k *ar)
        vfree(ar->debug.fw_crash_data);
        ar->debug.fw_crash_data = NULL;
 
+       vfree(ar->debug.cal_data);
+       ar->debug.cal_data = NULL;
+
        ath10k_debug_fw_stats_reset(ar);
 
        kfree(ar->debug.tpc_stats);