FAILED: patch "[PATCH] mmc: core: don't initialize block size from ext_csd if not" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b503087445ce7e45fabdee87ca9e460d5b5b5168 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <[email protected]>
Date: Thu, 14 Jan 2021 12:14:05 -0800
Subject: [PATCH] mmc: core: don't initialize block size from ext_csd if not
present

If extended CSD was not available, the eMMC driver would incorrectly set the block size to 0, as the data_sector_size field of ext_csd was never initialized. This issue was exposed by commit 817046ecddbc ("block: Align max_hw_sectors to logical blocksize") which caused max_sectors and max_hw_sectors to be set to 0 after setting the block size to 0, resulting in a kernel panic in bio_split when attempting to read from the device. Fix it by only reading the block size from ext_csd if it is available.

index de7cb0369c30..002426e3cf76 100644
@@ -384,8 +384,10 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 		     "merging was advertised but not possible");
 	blk_queue_max_segments(mq->queue, mmc_get_max_segments(host));
 
-	if (mmc_card_mmc(card))
+	if (mmc_card_mmc(card) && card->ext_csd.data_sector_size) {
 		block_size = card->ext_csd.data_sector_size;
+		WARN_ON(block_size != 512 && block_size != 4096);
+	}
 
 	blk_queue_logical_block_size(mq->queue, block_size);
 	/*