From 5a12c443b892b7b35d770db59da71a2cbb73ce91 Mon Sep 17 00:00:00 2001
From: Freddie Chopin <freddie.chopin@gmail.com>
Date: Fri, 9 Aug 2019 23:02:33 +0200
Subject: [PATCH] Revert "Don't bypass cache in `lfs_cache_prog()` and
 `lfs_cache_read()`"

This reverts commit fdd239fe21a3721dc7fb55a9cf816544af7e9647.

Bypassing cache turned out to be a mistake which causes more problems
than it solves. Device driver should deal with alignment if this is
required - trying to do that in a file system is not a viable solution
anyway.
---
 lfs.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lfs.c b/lfs.c
index b10c186..a96f327 100644
--- a/lfs.c
+++ b/lfs.c
@@ -71,6 +71,21 @@ static int lfs_bd_read(lfs_t *lfs,
             diff = lfs_min(diff, rcache->off-off);
         }
 
+        if (size >= hint && off % lfs->cfg->read_size == 0 &&
+                size >= lfs->cfg->read_size) {
+            // bypass cache?
+            diff = lfs_aligndown(diff, lfs->cfg->read_size);
+            int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
+            if (err) {
+                return err;
+            }
+
+            data += diff;
+            off += diff;
+            size -= diff;
+            continue;
+        }
+
         // load to cache, first condition can no longer fail
         LFS_ASSERT(block < lfs->cfg->block_count);
         rcache->block = block;