ath10k: fix error while writing 'simulate_fw_crash' debugfs

Fix invalid argument error while writing 'simulate_fw_crash',
though the funcionality is working fine we get an error 'invalid
argument' because 'count' value is not returned properly
(no reason to reduce the count value for removing the newline)

Fixes the below write error:

/sys/kernel/debug/ieee80211/phy0/ath10k# echo hw-restart >
simulate_fw_crash
-bash: echo: write error: Invalid argument

Also move the 'conf_mutex' as it is really not required for
fetching the userspace buffer.

Reported-by: Maharaja Kennadyrajan <c_mkenna@qti.qualcomm.com>
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
Signed-off-by: Maharaja Kennadyrajan <c_mkenna@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index e2511550fbb86c5fcafb88d0e6c1504bd0bd8337..54cb6292b8793838c44347afbddbd2258cb90173 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -609,25 +609,23 @@ static ssize_t ath10k_write_simulate_fw_crash(struct file *file,
        char buf[32];
        int ret;
 
-       mutex_lock(&ar->conf_mutex);
-
        simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count);
 
        /* make sure that buf is null terminated */
        buf[sizeof(buf) - 1] = 0;
 
+       /* drop the possible '\n' from the end */
+       if (buf[count - 1] == '\n')
+               buf[count - 1] = 0;
+
+       mutex_lock(&ar->conf_mutex);
+
        if (ar->state != ATH10K_STATE_ON &&
            ar->state != ATH10K_STATE_RESTARTED) {
                ret = -ENETDOWN;
                goto exit;
        }
 
-       /* drop the possible '\n' from the end */
-       if (buf[count - 1] == '\n') {
-               buf[count - 1] = 0;
-               count--;
-       }
-
        if (!strcmp(buf, "soft")) {
                ath10k_info(ar, "simulating soft firmware crash\n");
                ret = ath10k_wmi_force_fw_hang(ar, WMI_FORCE_FW_HANG_ASSERT, 0);