[patch 05/13] MegaRAID driver management char device moved to misc

[patch 05/13] MegaRAID driver management char device moved to misc

[akpm]

From: Thomas Horsten <thomas@horsten.com>

The MegaRAID driver's common management module (megaraid_mm.c) creates a
char device used by the management tool "megarc" from LSI Logic (and
possibly other management tools).

In 2.6 with udev, this device doesn't get created because it is not
registered in sysfs.

I first fixed this by registering a class "megaraid_mm", but realized that
this should probably be moved to misc devices, instead of taking up a char
major.  This is because only 1 device is used, even if there are multiple
adapters - the minor is never used (the adapter info is in the ioctl block
sent to the driver, not detected based on the minor number as one might
think).  So it is a complete waste to have an entire major taken by this.

So it now uses a misc device which I named "megadev0" (the name that megarc
expects), and has a dynamic minor (previoulsy a dynamic major was used).

I have tested this on my own system with the megarc tool, and it works just
as fine as before (only now the device gets created correctly by udev).

Cc: <thomas.horsten@gmail.com>
Cc: Neela Syam Kolli <Neela.Kolli@engenio.com>
Cc: "Ju, Seokmann" <Seokmann.Ju@lsil.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/scsi/megaraid/megaraid_mm.c |   20 +++++++++++++-------
 drivers/scsi/megaraid/megaraid_mm.h |    1 +
 2 files changed, 14 insertions(+), 7 deletions(-)

diff -puN drivers/scsi/megaraid/megaraid_mm.c~megaraid-driver-management-char-device-moved-to-misc drivers/scsi/megaraid/megaraid_mm.c
--- a/drivers/scsi/megaraid/megaraid_mm.c~megaraid-driver-management-char-device-moved-to-misc
+++ a/drivers/scsi/megaraid/megaraid_mm.c
@@ -59,7 +59,6 @@ EXPORT_SYMBOL(mraid_mm_register_adp);
 EXPORT_SYMBOL(mraid_mm_unregister_adp);
 EXPORT_SYMBOL(mraid_mm_adapter_app_handle);
 
-static int majorno;
 static uint32_t drvr_ver	= 0x02200207;
 
 static int adapters_count_g;
@@ -76,6 +75,12 @@ static const struct file_operations lsi_
 	.owner	= THIS_MODULE,
 };
 
+static struct miscdevice megaraid_mm_dev = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name   = "megadev0",
+	.fops   = &lsi_fops,
+};
+
 /**
  * mraid_mm_open - open routine for char node interface
  * @inode	: unused
@@ -1184,15 +1189,16 @@ mraid_mm_teardown_dma_pools(mraid_mmadp_
 static int __init
 mraid_mm_init(void)
 {
+	int err;
+
 	// Announce the driver version
 	con_log(CL_ANN, (KERN_INFO "megaraid cmm: %s %s\n",
 		LSI_COMMON_MOD_VERSION, LSI_COMMON_MOD_EXT_VERSION));
 
-	majorno = register_chrdev(0, "megadev", &lsi_fops);
-
-	if (majorno < 0) {
-		con_log(CL_ANN, ("megaraid cmm: cannot get major\n"));
-		return majorno;
+	err = misc_register(&megaraid_mm_dev);
+	if (err < 0) {
+		con_log(CL_ANN, ("megaraid cmm: cannot register misc device\n"));
+		return err;
 	}
 
 	init_waitqueue_head(&wait_q);
@@ -1230,7 +1236,7 @@ mraid_mm_exit(void)
 {
 	con_log(CL_DLEVEL1 , ("exiting common mod\n"));
 
-	unregister_chrdev(majorno, "megadev");
+	misc_deregister(&megaraid_mm_dev);
 }
 
 module_init(mraid_mm_init);
diff -puN drivers/scsi/megaraid/megaraid_mm.h~megaraid-driver-management-char-device-moved-to-misc drivers/scsi/megaraid/megaraid_mm.h
--- a/drivers/scsi/megaraid/megaraid_mm.h~megaraid-driver-management-char-device-moved-to-misc
+++ a/drivers/scsi/megaraid/megaraid_mm.h
@@ -22,6 +22,7 @@
 #include <linux/moduleparam.h>
 #include <linux/pci.h>
 #include <linux/list.h>
+#include <linux/miscdevice.h>
 
 #include "mbox_defs.h"
 #include "megaraid_ioctl.h"
_

Re: [patch 05/13] MegaRAID driver management char device moved to misc

[James Bottomley]

On Mon, 2008-02-04 at 23:53 -0800, akpm@linux-foundation.org wrote:
> From: Thomas Horsten <thomas@horsten.com>
> 
> The MegaRAID driver's common management module (megaraid_mm.c) creates a
> char device used by the management tool "megarc" from LSI Logic (and
> possibly other management tools).
> 
> In 2.6 with udev, this device doesn't get created because it is not
> registered in sysfs.
> 
> I first fixed this by registering a class "megaraid_mm", but realized that
> this should probably be moved to misc devices, instead of taking up a char
> major.  This is because only 1 device is used, even if there are multiple
> adapters - the minor is never used (the adapter info is in the ioctl block
> sent to the driver, not detected based on the minor number as one might
> think).  So it is a complete waste to have an entire major taken by this.
> 
> So it now uses a misc device which I named "megadev0" (the name that megarc
> expects), and has a dynamic minor (previoulsy a dynamic major was used).
> 
> I have tested this on my own system with the megarc tool, and it works just
> as fine as before (only now the device gets created correctly by udev).
> 
> Cc: <thomas.horsten@gmail.com>
> Cc: Neela Syam Kolli <Neela.Kolli@engenio.com>
> Cc: "Ju, Seokmann" <Seokmann.Ju@lsil.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Neela and Sekomann or Sumant, can I ping on this ... I've no idea what
this will do to the raid management tools, so I really need someone to
sign off on this.

James

RE: [patch 05/13] MegaRAID driver management char device moved tomisc

[Patro, Sumant]

James, I acked this patch on 11/28.

We are fine with the change proposed.

Regards,

Sumant



-----Original Message-----
From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com] 
Sent: Thursday, February 07, 2008 4:41 PM
To: akpm@linux-foundation.org
Cc: linux-scsi@vger.kernel.org; thomas@horsten.com; Kolli, Neela;
Seokmann.Ju@lsil.com; thomas.horsten@gmail.com; Patro, Sumant
Subject: Re: [patch 05/13] MegaRAID driver management char device moved
tomisc


On Mon, 2008-02-04 at 23:53 -0800, akpm@linux-foundation.org wrote:
> From: Thomas Horsten <thomas@horsten.com>
> 
> The MegaRAID driver's common management module (megaraid_mm.c) creates

> a char device used by the management tool "megarc" from LSI Logic (and

> possibly other management tools).
> 
> In 2.6 with udev, this device doesn't get created because it is not 
> registered in sysfs.
> 
> I first fixed this by registering a class "megaraid_mm", but realized 
> that this should probably be moved to misc devices, instead of taking 
> up a char major.  This is because only 1 device is used, even if there

> are multiple adapters - the minor is never used (the adapter info is 
> in the ioctl block sent to the driver, not detected based on the minor

> number as one might think).  So it is a complete waste to have an
entire major taken by this.
> 
> So it now uses a misc device which I named "megadev0" (the name that 
> megarc expects), and has a dynamic minor (previoulsy a dynamic major
was used).
> 
> I have tested this on my own system with the megarc tool, and it works

> just as fine as before (only now the device gets created correctly by
udev).
> 
> Cc: <thomas.horsten@gmail.com>
> Cc: Neela Syam Kolli <Neela.Kolli@engenio.com>
> Cc: "Ju, Seokmann" <Seokmann.Ju@lsil.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Neela and Sekomann or Sumant, can I ping on this ... I've no idea what
this will do to the raid management tools, so I really need someone to
sign off on this.

James

RE: [patch 05/13] MegaRAID driver management char device moved tomisc

[James Bottomley]

On Thu, 2008-02-07 at 19:47 -0700, Patro, Sumant wrote:
> James, I acked this patch on 11/28.

Sorry about that ... that's in the window where my server dropped of the
internet while I was on holiday, so I didn't get the email, I'm afraid

> We are fine with the change proposed.

Great, will add it.

James