1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e55cde6d436d..59b452d5dc81 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -58,6 +58,9 @@
  */
 #define MMC_BKOPS_MAX_TIMEOUT   (4 * 60 * 1000) /* max time to wait in ms */
 
+/* The max erase timeout, used when host->max_busy_timeout isn't specified */
+#define MMC_ERASE_TIMEOUT_MS    (60 * 1000) /* 60 s */
+
 static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };
 
 /*
@@ -2352,6 +2355,8 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
         struct mmc_host *host = card->host;
         unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout;
         unsigned int last_timeout = 0;
+        unsigned int max_busy_timeout = host->max_busy_timeout ?
+                        host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS;
 
         if (card->erase_shift) {
                 max_qty = UINT_MAX >> card->erase_shift;
@@ -2374,15 +2379,15 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
          * matter what size of 'host->max_busy_timeout', but if the
          * 'host->max_busy_timeout' is large enough for more discard sectors,
          * then we can continue to increase the max discard sectors until we
-         * get a balance value.
+         * get a balance value. In cases when the 'host->max_busy_timeout'
+         * isn't specified, use the default max erase timeout.
          */
         do {
                 y = 0;
                 for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) {
                         timeout = mmc_erase_timeout(card, arg, qty + x);
 
-                        if (qty + x > min_qty &&
-                            timeout > host->max_busy_timeout)
+                        if (qty + x > min_qty && timeout > max_busy_timeout)
                                 break;
 
                         if (timeout < last_timeout)
@@ -2427,9 +2432,6 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
         struct mmc_host *host = card->host;
         unsigned int max_discard, max_trim;
 
-        if (!host->max_busy_timeout)
-                return UINT_MAX;
-
         /*
          * Without erase_group_def set, MMC erase timeout depends on clock
          * frequence which can change.  In that case, the best choice is
@@ -2447,7 +2449,8 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
                 max_discard = 0;
         }
         pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
-                 mmc_hostname(host), max_discard, host->max_busy_timeout);
+                mmc_hostname(host), max_discard, host->max_busy_timeout ?
+                host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS);
         return max_discard;
 }
 EXPORT_SYMBOL(mmc_calc_max_discard);