Merge tag 'mhi-fixes-for-v6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi into char-misc-next

Manivannan writes:

MHI Endpoint
============

- Increment the rd_offset after writing the buffer to avoid MHI host accessing
  the incomplete/wrong buffer element.

* tag 'mhi-fixes-for-v6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi:
  bus: mhi: ep: Update read pointer only after buffer is written

Author: gregkh

drivers/bus/mhi/ep/ring.c

@@ -131,19 +131,23 @@ int mhi_ep_ring_add_element(struct mhi_ep_ring *ring, struct mhi_ring_element *e
 	}
 
 	old_offset = ring->rd_offset;
-	mhi_ep_ring_inc_index(ring);
 
 	dev_dbg(dev, "Adding an element to ring at offset (%zu)\n", ring->rd_offset);
+	buf_info.host_addr = ring->rbase + (old_offset * sizeof(*el));
+	buf_info.dev_addr = el;
+	buf_info.size = sizeof(*el);
+
+	ret = mhi_cntrl->write_sync(mhi_cntrl, &buf_info);
+	if (ret)
+		return ret;
+
+	mhi_ep_ring_inc_index(ring);
 
 	/* Update rp in ring context */
 	rp = cpu_to_le64(ring->rd_offset * sizeof(*el) + ring->rbase);
 	memcpy_toio((void __iomem *) &ring->ring_ctx->generic.rp, &rp, sizeof(u64));
 
-	buf_info.host_addr = ring->rbase + (old_offset * sizeof(*el));
-	buf_info.dev_addr = el;
-	buf_info.size = sizeof(*el);
-
-	return mhi_cntrl->write_sync(mhi_cntrl, &buf_info);
+	return ret;
 }
 
 void mhi_ep_ring_init(struct mhi_ep_ring *ring, enum mhi_ep_ring_type type, u32 id)