mmc_block: inform block layer about sector count restriction

Make sure we consider the maximum block count when we tell the block
layer about the maximum sector count. That way we don't have to chop
up the request ourselves.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/card/block.c

@@ -215,8 +215,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
 	struct mmc_blk_request brq;
-	int ret = 1, data_size, i;
-	struct scatterlist *sg;
+	int ret = 1;
 
 	mmc_claim_host(card->host);
 
@@ -237,8 +236,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 		brq.stop.arg = 0;
 		brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 		brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
-		if (brq.data.blocks > card->host->max_blk_count)
-			brq.data.blocks = card->host->max_blk_count;
 
 		if (brq.data.blocks > 1) {
 			/* SPI multiblock writes terminate using a special
@@ -270,24 +267,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 
 		mmc_queue_bounce_pre(mq);
 
-		/*
-		 * Adjust the sg list so it is the same size as the
-		 * request.
-		 */
-		if (brq.data.blocks !=
-		    (req->nr_sectors >> (md->block_bits - 9))) {
-			data_size = brq.data.blocks * brq.data.blksz;
-			for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
-				data_size -= sg->length;
-				if (data_size <= 0) {
-					sg->length += data_size;
-					i++;
-					break;
-				}
-			}
-			brq.data.sg_len = i;
-		}
-
 		mmc_wait_for_req(card->host, &brq.mrq);
 
 		mmc_queue_bounce_post(mq);

drivers/mmc/card/queue.c

@@ -142,12 +142,19 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
 			bouncesz = host->max_req_size;
 		if (bouncesz > host->max_seg_size)
 			bouncesz = host->max_seg_size;
+		if (bouncesz > (host->max_blk_count * 512))
+			bouncesz = host->max_blk_count * 512;
 
-		mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-		if (!mq->bounce_buf) {
-			printk(KERN_WARNING "%s: unable to allocate "
-				"bounce buffer\n", mmc_card_name(card));
-		} else {
+		if (bouncesz > 512) {
+			mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+			if (!mq->bounce_buf) {
+				printk(KERN_WARNING "%s: unable to "
+					"allocate bounce buffer\n",
+					mmc_card_name(card));
+			}
+		}
+
+		if (mq->bounce_buf) {
 			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 			blk_queue_max_sectors(mq->queue, bouncesz / 512);
 			blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
@@ -175,7 +182,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
 
 	if (!mq->bounce_buf) {
 		blk_queue_bounce_limit(mq->queue, limit);
-		blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
+		blk_queue_max_sectors(mq->queue,
+			min(host->max_blk_count, host->max_req_size / 512));
 		blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
 		blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
 		blk_queue_max_segment_size(mq->queue, host->max_seg_size);