[PATCH] fix for mtd partitions for erase_size != 2^X

[PATCH] fix for mtd partitions for erase_size != 2^X

[Peter Menzebach]

[-- Attachment #1: Type: text/plain, Size: 147 bytes --]

Here a trivial patch,
which allows correct creation of mtd partitions, which have erase sizes 
which are not a power of 2. 

Best regards
Peter 



[-- Attachment #2: patch.mtdpart.c --]
[-- Type: text/plain, Size: 691 bytes --]

--- drivers/mtd/mtdpart.c.orig	2005-09-23 09:28:07.000000000 +0200
+++ drivers/mtd/mtdpart.c	2005-09-23 09:29:37.000000000 +0200
@@ -465,9 +465,9 @@
 		if (slave->offset == MTDPART_OFS_APPEND)
 			slave->offset = cur_offset;
 		if (slave->offset == MTDPART_OFS_NXTBLK) {
-			u_int32_t emask = master->erasesize-1;
-			slave->offset = (cur_offset + emask) & ~emask;
-			if (slave->offset != cur_offset) {
+			slave->offset = cur_offset;
+			if ((cur_offset % master->erasesize) != 0) {
+				slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
 				printk(KERN_NOTICE "Moving partition %d: "
 				       "0x%08x -> 0x%08x\n", i,
 				       cur_offset, slave->offset);

[PATCH] fix for mtd partitions for erase_size != 2^X

[Peter Menzebach]

Here a trivial patch,
which allows correct creation of mtd partitions, which have erase sizes 
which are not a power of 2.

Best regards
Peter

Sorry, I didn't succeed to get the patch accepted by the mailing list as 
attachment.

-- 
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1

--- drivers/mtd/mtdpart.c.orig	2005-09-23 09:28:07.000000000 +0200
+++ drivers/mtd/mtdpart.c	2005-09-23 09:29:37.000000000 +0200
@@ -465,9 +465,9 @@
  		if (slave->offset == MTDPART_OFS_APPEND)
  			slave->offset = cur_offset;
  		if (slave->offset == MTDPART_OFS_NXTBLK) {
-			u_int32_t emask = master->erasesize-1;
-			slave->offset = (cur_offset + emask) & ~emask;
-			if (slave->offset != cur_offset) {
+			slave->offset = cur_offset;
+			if ((cur_offset % master->erasesize) != 0) {
+				slave->offset = ((cur_offset / master->erasesize) + 1) * 
master->erasesize;
  				printk(KERN_NOTICE "Moving partition %d: "
  				       "0x%08x -> 0x%08x\n", i,
  				       cur_offset, slave->offset);

[PATCH] fix for mtd partitions for erase_size != 2^X

[Peter Menzebach]

Here a trivial patch,
which allows correct creation of mtd partitions, which have erase sizes
which are not a power of 2.

Best regards
Peter

Sorry, I didn't succeed to get the patch accepted by the mailing list as
attachment.

--- drivers/mtd/mtdpart.c.orig    2005-09-23 09:28:07.000000000 +0200
+++ drivers/mtd/mtdpart.c    2005-09-23 09:29:37.000000000 +0200
@@ -465,9 +465,9 @@
          if (slave->offset == MTDPART_OFS_APPEND)
              slave->offset = cur_offset;
          if (slave->offset == MTDPART_OFS_NXTBLK) {
-            u_int32_t emask = master->erasesize-1;
-            slave->offset = (cur_offset + emask) & ~emask;
-            if (slave->offset != cur_offset) {
+            slave->offset = cur_offset;
+            if ((cur_offset % master->erasesize) != 0) {
+                slave->offset = ((cur_offset / master->erasesize) + 1) 
* master->erasesize;
                  printk(KERN_NOTICE "Moving partition %d: "
                         "0x%08x -> 0x%08x\n", i,
                         cur_offset, slave->offset);

Re: [PATCH] fix for mtd partitions for erase_size != 2^X

[Jörn Engel]

On Fri, 23 September 2005 20:02:42 +0200, Peter Menzebach wrote:
> 
> Here a trivial patch,
> which allows correct creation of mtd partitions, which have erase sizes
> which are not a power of 2.
> 
> Best regards
> Peter
> 
> Sorry, I didn't succeed to get the patch accepted by the mailing list as
> attachment.

I actually prefer inline.  Except that your mailer seems to have
messed things up - grr.

> --- drivers/mtd/mtdpart.c.orig    2005-09-23 09:28:07.000000000 +0200
> +++ drivers/mtd/mtdpart.c    2005-09-23 09:29:37.000000000 +0200
> @@ -465,9 +465,9 @@
>          if (slave->offset == MTDPART_OFS_APPEND)
>              slave->offset = cur_offset;
>          if (slave->offset == MTDPART_OFS_NXTBLK) {
> -            u_int32_t emask = master->erasesize-1;
> -            slave->offset = (cur_offset + emask) & ~emask;
> -            if (slave->offset != cur_offset) {
> +            slave->offset = cur_offset;
> +            if ((cur_offset % master->erasesize) != 0) {
> +                slave->offset = ((cur_offset / master->erasesize) + 1) 
> * master->erasesize;
>                  printk(KERN_NOTICE "Moving partition %d: "
>                         "0x%08x -> 0x%08x\n", i,
>                         cur_offset, slave->offset);

Looks complicated.  I guess we could use the equivalent of this:
#define ALIGN(x,a) (((x)+(a)-1)&~((a)-1))
in some header.  Then your patch would be as simple as

         if (slave->offset == MTDPART_OFS_APPEND)
             slave->offset = cur_offset;
         if (slave->offset == MTDPART_OFS_NXTBLK) {
-            u_int32_t emask = master->erasesize-1;
-            slave->offset = (cur_offset + emask) & ~emask;
+	     slave->offset = TRUE_ALIGN(cur_offset, master->erasesize);
             if (slave->offset != cur_offset) {
                 printk(KERN_NOTICE "Moving partition %d: "
                        "0x%08x -> 0x%08x\n", i,

Maybe this:
#define TRUE_ALIGN(x,a) (((x)+(a)-1) - ((x)+(a)-1) % a)

The macro is still complicated, but we just have to get it right once.

Jörn

-- 
Public Domain  - Free as in Beer
General Public - Free as in Speech
BSD License    - Free as in Enterprise
Shared Source  - Free as in "Work will make you..."

Re: [PATCH] fix for mtd partitions for erase_size != 2^X

[Peter Menzebach]

Jörn Engel wrote:
> Maybe this:
> #define TRUE_ALIGN(x,a) (((x)+(a)-1) - ((x)+(a)-1) % a)
> 
> The macro is still complicated, but we just have to get it right once.
> 
> Jörn
> 
Are you sure, this is not as complicated as my version ;) ?
But if you like it, no problem.

Shall I resubmit the patch?

Is there any known good way to submit a patch here? I have two mailer 
here, but the mailing list refuses both (as attachment and inline 
attachment).

Best regards
Peter

-- 
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1

Re: [PATCH] fix for mtd partitions for erase_size != 2^X

[Peter Menzebach]

Jörn Engel wrote:
> On Fri, 23 September 2005 20:02:42 +0200, Peter Menzebach wrote:
> 
>>Here a trivial patch,
>>which allows correct creation of mtd partitions, which have erase sizes
>>which are not a power of 2.
>>
>>Best regards
>>Peter
>>
>>Sorry, I didn't succeed to get the patch accepted by the mailing list as
>>attachment.
> 
> 
> I actually prefer inline.  Except that your mailer seems to have
> messed things up - grr.
> 
> 
>>--- drivers/mtd/mtdpart.c.orig    2005-09-23 09:28:07.000000000 +0200
>>+++ drivers/mtd/mtdpart.c    2005-09-23 09:29:37.000000000 +0200
>>@@ -465,9 +465,9 @@
>>         if (slave->offset == MTDPART_OFS_APPEND)
>>             slave->offset = cur_offset;
>>         if (slave->offset == MTDPART_OFS_NXTBLK) {
>>-            u_int32_t emask = master->erasesize-1;
>>-            slave->offset = (cur_offset + emask) & ~emask;
>>-            if (slave->offset != cur_offset) {
>>+            slave->offset = cur_offset;
>>+            if ((cur_offset % master->erasesize) != 0) {
>>+                slave->offset = ((cur_offset / master->erasesize) + 1) 
>>* master->erasesize;
>>                 printk(KERN_NOTICE "Moving partition %d: "
>>                        "0x%08x -> 0x%08x\n", i,
>>                        cur_offset, slave->offset);
> 
> 
> Looks complicated.  I guess we could use the equivalent of this:
> #define ALIGN(x,a) (((x)+(a)-1)&~((a)-1))
> in some header.  Then your patch would be as simple as
> 
>          if (slave->offset == MTDPART_OFS_APPEND)
>              slave->offset = cur_offset;
>          if (slave->offset == MTDPART_OFS_NXTBLK) {
> -            u_int32_t emask = master->erasesize-1;
> -            slave->offset = (cur_offset + emask) & ~emask;
> +	     slave->offset = TRUE_ALIGN(cur_offset, master->erasesize);
>              if (slave->offset != cur_offset) {
>                  printk(KERN_NOTICE "Moving partition %d: "
>                         "0x%08x -> 0x%08x\n", i,
> 
> Maybe this:
> #define TRUE_ALIGN(x,a) (((x)+(a)-1) - ((x)+(a)-1) % a)
> 
> The macro is still complicated, but we just have to get it right once.
> 
> Jörn
> 
Here the patch again. As the macro does not seem to reduce the 
complexity of the line seriously and would be used only once, I did put 
in a comment, which explains inline, what should go on there.

The patch now as link:
http://www.mw-itcon.de/patches/patch.dataflash.mtdpart.c

Best regards
Peter


-- 
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1

Re: [PATCH] fix for mtd partitions for erase_size != 2^X

[Jörn Engel]

On Fri, 30 September 2005 13:23:44 +0200, Peter Menzebach wrote:
> >
> Here the patch again. As the macro does not seem to reduce the 
> complexity of the line seriously and would be used only once, I did put 
> in a comment, which explains inline, what should go on there.

All right.  I still don't like it, but since I don't have any better
idea...

Jörn

-- 
Das Aufregende am Schreiben ist es, eine Ordnung zu schaffen, wo
vorher keine existiert hat.
-- Doris Lessing