wil6210: Fix division by zero in wil_vring_debugfs_show

On some platforms get_cycles() implemented to allways return 0.
On such platforms "Division by zero" bug was triggered.

Signed-off-by: Boris Sorochkin <boriss@codeaurora.org>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index eb6de8cbdd7a..fd5975153386 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -103,23 +103,30 @@ static int wil_vring_debugfs_show(struct seq_file *s, void *data)
                                    % vring->size;
                         int avail = vring->size - used - 1;
                         char name[10];
+                        char sidle[10];
                         /* performance monitoring */
                         cycles_t now = get_cycles();
                         uint64_t idle = txdata->idle * 100;
                         uint64_t total = now - txdata->begin;
 
-                        do_div(idle, total);
+                        if (total != 0) {
+                                do_div(idle, total);
+                                snprintf(sidle, sizeof(sidle), "%3d%%",
+                                         (int)idle);
+                        } else {
+                                snprintf(sidle, sizeof(sidle), "N/A");
+                        }
                         txdata->begin = now;
                         txdata->idle = 0ULL;
 
                         snprintf(name, sizeof(name), "tx_%2d", i);
 
                         seq_printf(s,
-                                   "\n%pM CID %d TID %d BACK([%d] %d TU A%s) [%3d|%3d] idle %3d%%\n",
-                                   wil->sta[cid].addr, cid, tid,
-                                   txdata->agg_wsize, txdata->agg_timeout,
-                                   txdata->agg_amsdu ? "+" : "-",
-                                   used, avail, (int)idle);
+                                "\n%pM CID %d TID %d BACK([%d] %d TU A%s) [%3d|%3d] idle %s\n",
+                                wil->sta[cid].addr, cid, tid,
+                                txdata->agg_wsize, txdata->agg_timeout,
+                                txdata->agg_amsdu ? "+" : "-",
+                                used, avail, sidle);
 
                         wil_print_vring(s, wil, name, vring, '_', 'H');
                 }