diff mbox

[6/8] UBI: replace MTD_UBI_BEB_LIMIT with module parameter

Message ID 1345214124-5478-7-git-send-email-richard.genoud@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Richard Genoud Aug. 17, 2012, 2:35 p.m. UTC
This patch provides the possibility to adjust the "maximum expected number of
bad blocks per 1024 blocks" (max_beb_per1024) for each mtd device.

The majority of NAND devices have their max_beb_per1024 equal to 20, but
sometimes it's more.
Now, we can adjust that via a kernel parameter:
ubi.mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024]]

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/mtd/ubi/Kconfig |    2 ++
 drivers/mtd/ubi/build.c |   38 ++++++++++++++++++++++++--------------
 2 files changed, 26 insertions(+), 14 deletions(-)

Comments

Shmulik Ladkani Aug. 19, 2012, 9:26 a.m. UTC | #1
Hi Richard,

On Fri, 17 Aug 2012 16:35:22 +0200 Richard Genoud <richard.genoud@gmail.com> wrote:
> +		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
> +		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0 or not set)\n"
> +		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
> +		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0 or not set)\n"

Looks like "mtd=/dev/mtd1,,25" is invalid, although we state "default
value if 0 or not set".

Also, lines are exceeding 80 chars, not sure this is more readable than
if they were broken.

Regards,
Shmulik
Richard Genoud Aug. 20, 2012, 7:38 a.m. UTC | #2
2012/8/19 Shmulik Ladkani <shmulik.ladkani@gmail.com>:
> Hi Richard,
>
> On Fri, 17 Aug 2012 16:35:22 +0200 Richard Genoud <richard.genoud@gmail.com> wrote:
>> +                   "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
>> +                   "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0 or not set)\n"
>> +                   "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
>> +                   __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0 or not set)\n"
>
> Looks like "mtd=/dev/mtd1,,25" is invalid, although we state "default
> value if 0 or not set".
I'm going to check that.
>
> Also, lines are exceeding 80 chars, not sure this is more readable than
> if they were broken.
Actually, I didn't split those lines to make checkpatch happy.
Checkpatch.pl doesn't like split strings because they are hard to grep.
So there's an exception on the 80 column rule for strings.

>
> Regards,
> Shmulik
Richard Genoud Aug. 20, 2012, 8:21 a.m. UTC | #3
2012/8/20 Richard Genoud <richard.genoud@gmail.com>:
> 2012/8/19 Shmulik Ladkani <shmulik.ladkani@gmail.com>:
>> Hi Richard,
>>
>> On Fri, 17 Aug 2012 16:35:22 +0200 Richard Genoud <richard.genoud@gmail.com> wrote:
>>> +                   "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
>>> +                   "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0 or not set)\n"
>>> +                   "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
>>> +                   __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0 or not set)\n"
>>
>> Looks like "mtd=/dev/mtd1,,25" is invalid, although we state "default
>> value if 0 or not set".
> I'm going to check that.
I made a patch to accept empty string value.
I'll send it with the rest of the patch serie.

Regards,
Richard.
diff mbox

Patch

diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig
index f326877..8b67bac 100644
--- a/drivers/mtd/ubi/Kconfig
+++ b/drivers/mtd/ubi/Kconfig
@@ -51,6 +51,8 @@  config MTD_UBI_BEB_LIMIT
 	  MTD partitions of the same size, UBI will reserve 40 eraseblocks when
 	  attaching a partition.
 
+	  This option can be overridden by the kernel parameter ubi.mtd.
+
 	  Leave the default value if unsure.
 
 config MTD_UBI_GLUEBI
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index ec7311f..cc05022 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -47,7 +47,7 @@ 
 #define MTD_PARAM_LEN_MAX 64
 
 /* Maximum number of comma-separated items in ht 'mtd=' parameter */
-#define MTD_PARAM_MAX_COUNT 2
+#define MTD_PARAM_MAX_COUNT 3
 
 #ifdef CONFIG_MTD_UBI_MODULE
 #define ubi_is_module() 1
@@ -60,10 +60,12 @@ 
  * @name: MTD character device node path, MTD device name, or MTD device number
  *        string
  * @vid_hdr_offs: VID header offset
+ * @max_beb_per1024: maximum expected number of bad blocks per 1024 erase blocks
  */
 struct mtd_dev_param {
 	char name[MTD_PARAM_LEN_MAX];
 	int vid_hdr_offs;
+	int max_beb_per1024;
 };
 
 /* Numbers of elements set in the @mtd_dev_param array */
@@ -1222,8 +1224,7 @@  static int __init ubi_init(void)
 
 		mutex_lock(&ubi_devices_mutex);
 		err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
-					 p->vid_hdr_offs,
-					 CONFIG_MTD_UBI_BEB_LIMIT);
+					 p->vid_hdr_offs, p->max_beb_per1024);
 		mutex_unlock(&ubi_devices_mutex);
 		if (err < 0) {
 			ubi_err("cannot attach mtd%d", mtd->index);
@@ -1343,6 +1344,7 @@  static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 	char buf[MTD_PARAM_LEN_MAX];
 	char *pbuf = &buf[0];
 	char *tokens[MTD_PARAM_MAX_COUNT];
+	int err;
 
 	if (!val)
 		return -EINVAL;
@@ -1390,23 +1392,31 @@  static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 	if (p->vid_hdr_offs < 0)
 		return p->vid_hdr_offs;
 
+	if (tokens[2]) {
+		err = kstrtoint(tokens[2], 10, &p->max_beb_per1024);
+		if (err) {
+			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
+			       tokens[2]);
+			return -EINVAL;
+		}
+	}
+
 	mtd_devs += 1;
 	return 0;
 }
 
 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
-MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
-		      "mtd=<name|num|path>[,<vid_hdr_offs>].\n"
+MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024]].\n"
 		      "Multiple \"mtd\" parameters may be specified.\n"
-		      "MTD devices may be specified by their number, name, or "
-		      "path to the MTD character device node.\n"
-		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
-		      "header position to be used by UBI.\n"
-		      "Example 1: mtd=/dev/mtd0 - attach MTD device "
-		      "/dev/mtd0.\n"
-		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device "
-		      "with name \"content\" using VID header offset 1984, and "
-		      "MTD device number 4 with default VID header offset.");
+		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
+		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0 or not set)\n"
+		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
+		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0 or not set)\n"
+		      "\n"
+		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
+		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
+		      "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
+		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
 
 MODULE_VERSION(__stringify(UBI_VERSION));
 MODULE_DESCRIPTION("UBI - Unsorted Block Images");