mmc: core: Drop superfluous validations in mmc_hw|sw_reset()

The mmc_hw|sw_reset() APIs are designed to be called solely from upper
layers, which means drivers that operates on top of the struct mmc_card,
like the mmc block device driver and an SDIO functional driver.

Additionally, as long as the struct mmc_host has a valid pointer to a
struct mmc_card, the corresponding host->bus_ops pointer stays valid and
assigned.

For these reasons, let's drop the superfluous reference counting and the
redundant validations in mmc_hw|sw_reset().

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20210212131532.236775-1-ulf.hansson@linaro.org

drivers/mmc/core/block.c

@@ -947,7 +947,7 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
 	md->reset_done |= type;
 	err = mmc_hw_reset(host);
 	/* Ensure we switch back to the correct partition */
-	if (err != -EOPNOTSUPP) {
+	if (err) {
 		struct mmc_blk_data *main_md =
 			dev_get_drvdata(&host->card->dev);
 		int part_err;

drivers/mmc/core/core.c

@@ -2080,18 +2080,7 @@ int mmc_hw_reset(struct mmc_host *host)
 {
 	int ret;
 
-	if (!host->card)
-		return -EINVAL;
-
-	mmc_bus_get(host);
-	if (!host->bus_ops || host->bus_dead || !host->bus_ops->hw_reset) {
-		mmc_bus_put(host);
-		return -EOPNOTSUPP;
-	}
-
 	ret = host->bus_ops->hw_reset(host);
-	mmc_bus_put(host);
-
 	if (ret < 0)
 		pr_warn("%s: tried to HW reset card, got error %d\n",
 			mmc_hostname(host), ret);
@@ -2104,18 +2093,10 @@ int mmc_sw_reset(struct mmc_host *host)
 {
 	int ret;
 
-	if (!host->card)
-		return -EINVAL;
-
-	mmc_bus_get(host);
-	if (!host->bus_ops || host->bus_dead || !host->bus_ops->sw_reset) {
-		mmc_bus_put(host);
+	if (!host->bus_ops->sw_reset)
 		return -EOPNOTSUPP;
-	}
 
 	ret = host->bus_ops->sw_reset(host);
-	mmc_bus_put(host);
-
 	if (ret)
 		pr_warn("%s: tried to SW reset card, got error %d\n",
 			mmc_hostname(host), ret);