[PATCH v2] spl: mmc: Use correct MMC device when loading image

[Harald Seiler]

When attempting to load images from multiple MMC devices in sequence,
spl_mmc_load() chooses the wrong device from the second attempt onwards.

The reason is that MMC initialization is only done on its first call and
spl_mmc_load() will then continue using this same device for all future
calls.

Fix this by checking the devnum of the "cached" device struct against
the one which is requested.  If they match, use the cached one but if
they do not match, initialize the new device.

This fixes specifying multiple MMC devices in the SPL's boot order to
fall back when U-Boot Proper is corrupted or missing on the first
attempted MMC device.

Fixes: e1eb6ada4e38 ("spl: Make image loader infrastructure more universal")
Signed-off-by: Harald Seiler <hws at denx.de>
---

Notes:
    Changes in v2:
      - Make it work with CONFIG_SPL_BLK as well

 common/spl/spl_mmc.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
index e1a7d25bd0..1c12f69d96 100644
--- a/common/spl/spl_mmc.c
+++ b/common/spl/spl_mmc.c
@@ -361,6 +361,17 @@ int __weak spl_mmc_emmc_boot_partition(struct mmc *mmc)
 	return default_spl_mmc_emmc_boot_partition(mmc);
 }
 
+static int spl_mmc_get_mmc_devnum(struct mmc *mmc)
+{
+	struct blk_desc *block_dev;
+#if !CONFIG_IS_ENABLED(BLK)
+	block_dev = &mmc->block_dev;
+#else
+	block_dev = dev_get_uclass_plat(mmc->dev);
+#endif
+	return block_dev->devnum;
+}
+
 int spl_mmc_load(struct spl_image_info *spl_image,
 		 struct spl_boot_device *bootdev,
 		 const char *filename,
@@ -371,9 +382,11 @@ int spl_mmc_load(struct spl_image_info *spl_image,
 	u32 boot_mode;
 	int err = 0;
 	__maybe_unused int part = 0;
+	int mmc_dev;
 
-	/* Perform peripheral init only once */
-	if (!mmc) {
+	/* Perform peripheral init only once for an mmc device */
+	mmc_dev = spl_mmc_get_device_index(bootdev->boot_device);
+	if (!mmc || spl_mmc_get_mmc_devnum(mmc) != mmc_dev) {
 		err = spl_mmc_find_device(&mmc, bootdev->boot_device);
 		if (err)
 			return err;
-- 
2.36.1