ubi: move UBI-related faq entry from UBIFS section

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/faq/ubi.xml b/faq/ubi.xml
index 76ad9d9c450e8e20726b588a8470f51c77d7f91c..a7416d56ab7e49889c67b84f2529e9b8d6ea3238 100644 (file)
--- a/faq/ubi.xml
+++ b/faq/ubi.xml
@@ -32,6 +32,7 @@
        <li><a href="ubi.html#L_subpage">What is sub-page?</a></li>
        <li><a href="ubi.html#L_subpage_verify_fail">I get "ubi_io_write: error -5 while writing 512 bytes to PEB 5:512"</a></li>
        <li><a href="ubi.html#L_no_vid_header">I get "no VID header found at PEB 7923, only 0xFF bytes"</a></li>
+       <li><a href="ubifs.html#L_ecc_error">I get: "ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 47:4096, read 126976 bytes"</a></li>
        <li><a href="ubi.html#L_force_no_subpage">How to force UBI to ignore sub-pages?</a></li>
        <li><a href="ubi.html#L_flasher">How to implement UBI flasher?</a></li>
        <li><a href="ubi.html#L_bgt_thread">What does the "ubi_bgt0d" thread do?</a></li>
@@ -544,6 +545,37 @@ case.</p>
 
 
 
+<h2><a name="L_ecc_error">
+I see this UBI error: "ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 47:4096, read 126976 bytes"
+</a></h2>
+
+<p>The <code>-74</code> error code is <code>-EBADMSG</code> and means an ECC
+error. In other words, UBI tried to read some data from the flash, but the
+flash driver found that there is an uncorrectable ECC error, and returned
+<code>-EBADMSG</code>.</p>
+
+<p>There may be many reasons for this. It may be because your NAND driver is
+buggy, or you HW is buggy. We recommend you to validate the driver using the
+<a href="../doc/general.xml#L_mtd_tests">MTD tests</a>.</p>
+
+<p>The other possibility is that you failed to flash your UBI/UBIFS image
+properly. Try to erase your flash, then attach it to UBI/UBIFS without writing
+any image, and check if you still have these errors.</p>
+
+<p>If you do not have errors when you mount empty flash, it is probably indeed
+related to how you flash the UBI/UBIFS images. One typical problem is related
+to ECC calculation algorithm - read
+<a name="ubifs.html#L_why_ubiformat">here</a> for more information. Make sure
+that you use <a name="../doc/ubifs.html#L_usptools">ubiformat</a>), or make sure
+your flashing program skips 0xFF properly (see
+<a href="../doc/ubi.html#L_flasher_algo">here</a>).</p>
+
+<p>Another possibility is that your flash reports that it supports
+<a href="../doc/ubi.html#L_subpage">sub-pages</a>, but does not actually support
+them properly.</p>
+
+
+
 <h2><a name="L_force_no_subpage">How to force UBI to ignore sub-pages?"</a></h2>
 
 <p>If your NAND flash supports

diff --git a/faq/ubifs.xml b/faq/ubifs.xml
index 52c4c9cca45228f5c00d2718b34af70b0465a637..09f15e309dc3f3c66d3d5bcaf6025255dab0fe82 100644 (file)
--- a/faq/ubifs.xml
+++ b/faq/ubifs.xml
@@ -37,9 +37,8 @@
        <li><a href="ubifs.html#L_end_hole">Why my file has zeroes at the end after an unclean reboot?</a></li>
        <li><a href="ubifs.html#L_bgt_thread">What does the "ubifs_bgt0_0" thread do?</a></li>
        <li><a href="ubifs.html#L_sudden_ro">UBIFS suddenly became read-only - what is this?</a></li>
-       <li><a href="ubifs.html#L_lebsz_mismatch">I see this UBIFS error: "validate_sb: LEB size mismatch: 129024 in superblock, 126976 real"</a></li>
-       <li><a href="ubifs.html#L_ecc_error">I see this UBI error: "ubi_io_read: error -74 while reading 126976 bytes from PEB 47:4096, read 126976 bytes"</a></li>
-       <li><a href="ubifs.html#L_pdflush_blocked">I see this error: "INFO: task pdflush:110 blocked for more than 120 seconds"</a></li>
+       <li><a href="ubifs.html#L_lebsz_mismatch">I get: "validate_sb: LEB size mismatch: 129024 in superblock, 126976 real"</a></li>
+       <li><a href="ubifs.html#L_pdflush_blocked">I get: "INFO: task pdflush:110 blocked for more than 120 seconds"</a></li>
        <li><a href="ubifs.html#L_study_ubifs">I want to study UBIFS - any recommendations?</a></li>
 </ol>
 
@@ -1124,37 +1123,6 @@ correct LEB size via the <code>-e</code> option.</p>
 
 
 
-<h2><a name="L_ecc_error">
-I see this UBI error: "ubi_io_read: error -74 while reading 126976 bytes from PEB 47:4096, read 126976 bytes"
-</a></h2>
-
-<p>The <code>-74</code> error code is <code>-EBADMSG</code> and means an ECC
-error. In other words, UBI tried to read some data from the flash, but the
-flash driver found that there is an uncorrectable ECC error, and returned
-<code>-EBADMSG</code>.</p>
-
-<p>There may be many reasons for this. It may be because your NAND driver is
-buggy, or you HW is buggy. We recommend you to validate the driver using the
-<a href="../doc/general.xml#L_mtd_tests">MTD tests</a>.</p>
-
-<p>The other possibility is that you failed to flash your UBI/UBIFS image
-properly. Try to erase your flash, then attach it to UBI/UBIFS without writing
-any image, and check if you still have these errors.</p>
-
-<p>If you do not have errors when you mount empty flash, it is probably indeed
-related to how you flash the UBI/UBIFS images. One typical problem is related
-to ECC calculation algorithm - read
-<a name="ubifs.html#L_why_ubiformat">here</a> for more information. Make sure
-that you use <a name="../doc/ubifs.html#L_usptools">ubiformat</a>), or make sure
-your flashing program skips 0xFF properly (see
-<a href="../doc/ubi.html#L_flasher_algo">here</a>).</p>
-
-<p>Another possibility is that your flash does reports that it supports
-<a href="../doc/ubi.html#L_subpage">sub-page</a>, but does not actually support
-them properly. In that case the <code>-74</code> error happens when reading the
-first NAND page.</p>
-
-
 <h2><a name="L_pdflush_blocked">
 I see this error: "INFO: task pdflush:110 blocked for more than 120 seconds"
 </a></h2>