Hi,

On Fri, Jun 19, 2015 at 01:59:40PM +0000, David Fisher wrote:
> Hi all, 
> 
> I'm running 4.1-rc4 (Linaro 5.15) and trying to create a mass storage
> gadget via configfs, with default 1 LUN (lun.0). As the configfs
> progresses, I see "Number of LUNs=8". And when plugged in, the USB
> class specific getMaxLun request returns 7. In some Windows drivers
> (but not some others ?!), this MAX_LUN is taken into account and
> Windows tries to load class drivers for the additional 7 duff LUNs -
> resulting in "Device driver software was not correctly installed".
> 
> With debug added to f_mass_storage.c, I get the following :
> 
> [  469.402527] Number of LUNs=8 (fsg_common_set_nluns), with stack : 
> [  469.402611] CPU: 2 PID: 1590 Comm: mkdir Not tainted 
> 4.1.0-1-linaro-vexpress64 #15
> [  469.402680] Hardware name: FVP Base (DT)
> [  469.402730] Call trace:
> [  469.402808] [<ffffffc000089a58>] dump_backtrace+0x0/0x164
> [  469.402897] [<ffffffc000089bd8>] show_stack+0x1c/0x28
> [  469.402975] [<ffffffc00081a908>] dump_stack+0x84/0xc8
> [  469.403061] [<ffffffc000686938>] fsg_common_set_nluns+0x74/0xa4
> [  469.403152] [<ffffffc00068853c>] fsg_alloc_inst+0xe4/0x218
> [  469.403245] [<ffffffc00067f4a4>] try_get_usb_function_instance+0xb4/0xf0
> [  469.403342] [<ffffffc00067f634>] usb_get_function_instance+0x1c/0x68
> [  469.403425] [<ffffffc000681f2c>] function_make+0x78/0x138
> [  469.403510] [<ffffffc000245524>] configfs_mkdir+0x110/0x38c
> [  469.403591] [<ffffffc0001d72b8>] vfs_mkdir+0xf4/0x190
> [  469.403673] [<ffffffc0001dcc5c>] SyS_mkdirat+0xe4/0xf0
> [  469.403755] Mass Storage Function, version: 2009/09/11
> [  469.403823] LUN: removable file: (no medium)
> [  469.448719] Number of LUNs=8 (fsg_bind), with stack : 
> [  469.448799] CPU: 1 PID: 1576 Comm: start_dwusb_dev Not tainted 
> 4.1.0-1-linaro-vexpress64 #15
> [  469.448872] Hardware name: FVP Base (DT)
> [  469.448921] Call trace:
> [  469.448999] [<ffffffc000089a58>] dump_backtrace+0x0/0x164
> [  469.449088] [<ffffffc000089bd8>] show_stack+0x1c/0x28
> [  469.449167] [<ffffffc00081a908>] dump_stack+0x84/0xc8
> [  469.449253] [<ffffffc000687e90>] fsg_bind+0x1a4/0x1b0
> [  469.449340] [<ffffffc00067c4e8>] usb_add_function+0x74/0x188
> [  469.449437] [<ffffffc0006819a4>] configfs_composite_bind+0x22c/0x33c
> [  469.449524] [<ffffffc0006835f8>] udc_bind_to_driver+0x54/0x11c
> [  469.449609] [<ffffffc00068374c>] usb_udc_attach_driver+0x8c/0xc8
> [  469.449693] [<ffffffc00068212c>] gadget_dev_desc_UDC_store+0xc0/0x104
> [  469.449789] [<ffffffc00067f714>] gadget_info_attr_store+0x40/0x5c
> [  469.449875] [<ffffffc0002436d8>] configfs_write_file+0xc4/0x128
> [  469.449958] [<ffffffc0001cbbd0>] __vfs_write+0x44/0x130
> [  469.450039] [<ffffffc0001cc44c>] vfs_write+0x98/0x178
> [  469.450119] [<ffffffc0001ccce8>] SyS_write+0x50/0xb0
> 
> Configfs tree is :
> 
> drwxr-xr-x    3 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/
> drwxr-xr-x    6 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1
> drwxr-xr-x    2 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/os_desc
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/os_desc/qw_sign
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/os_desc/b_vendor_code
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/os_desc/use
> drwxr-xr-x    3 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/strings
> drwxr-xr-x    2 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/strings/0x409
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/strings/0x409/serialnumber
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/strings/0x409/product
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/strings/0x409/manufacturer
> drwxr-xr-x    3 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/configs
> drwxr-xr-x    3 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/configs/c.1
> lrwxrwxrwx    1 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/mass_storage.0 -> 
> ../../../../usb_gadget/g1/functions/mass_storage.0
> drwxr-xr-x    3 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/strings
> drwxr-xr-x    2 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409/configuration
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/bmAttributes
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/configs/c.1/MaxPower
> drwxr-xr-x    3 root     root             0 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/functions
> drwxr-xr-x    3 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0
> drwxr-xr-x    2 root     root             0 Jun 19 11:41 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0/nofua
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0/cdrom
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0/removable
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0/ro
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/lun.0/file
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/functions/mass_storage.0/stall
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/UDC
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bcdUSB
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bcdDevice
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/idProduct
> -rw-r--r--    1 root     root          4096 Jun 19 11:40 
> /sys/kernel/config/usb_gadget/g1/idVendor
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bMaxPacketSize0
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bDeviceProtocol
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bDeviceSubClass
> -rw-r--r--    1 root     root          4096 Jun 19 11:42 
> /sys/kernel/config/usb_gadget/g1/bDeviceClass
> 
> My interpretation of this is that common->nluns is only ever set in
> fsg_alloc_inst() "rc = fsg_common_set_nluns(opts->common,
> FSG_MAX_LUNS);"
> It doesn't take account of how many luns have been setup in the
> configfs tree.

your interpretation is correct.

> I have applied a hack/fix which works for me, though it needs tweaks
> and further testing given recent f_mass_storage.c patches I've seen
> floating about. This patch updates common->nluns on each
> fsg_common_create_lun(), and only prints Number of LUNs on fsg_bind
> when the configfs tree should be all there. Also assumes contiguous
> incrementing lun ids.

this makes sense to me although we need this in a proper patch format
(have a look at Documentation/SubmittingPatches and
Documentation/SubmitChecklist)

Michal, any comments to this diff ?

> diff --git a/drivers/usb/gadget/function/f_mass_storage.c 
> b/drivers/usb/gadget/function/f_mass_storage.c
> index 3cc109f..f502f00 100644
> --- a/drivers/usb/gadget/function/f_mass_storage.c
> +++ b/drivers/usb/gadget/function/f_mass_storage.c
> @@ -2796,8 +2796,6 @@ int fsg_common_set_nluns(struct fsg_common *common, int 
> nluns)
>       common->luns = curlun;
>       common->nluns = nluns;
>  
> -     pr_info("Number of LUNs=%d\n", common->nluns);
> -
>       return 0;
>  }
>  EXPORT_SYMBOL_GPL(fsg_common_set_nluns);
> @@ -2941,6 +2939,9 @@ int fsg_common_create_lun(struct fsg_common *common, 
> struct fsg_lun_config *cfg,
>                               p = "(error)";
>               }
>       }
> +
> +     common->nluns = id + 1;
> +
>       pr_info("LUN: %s%s%sfile: %s\n",
>             lun->removable ? "removable " : "",
>             lun->ro ? "read only " : "",
> @@ -2973,8 +2974,6 @@ int fsg_common_create_luns(struct fsg_common *common, 
> struct fsg_config *cfg)
>                       goto fail;
>       }
>  
> -     pr_info("Number of LUNs=%d\n", common->nluns);
> -
>       return 0;
>  
>  fail:
> @@ -3121,6 +3120,8 @@ static int fsg_bind(struct usb_configuration *c, struct 
> usb_function *f)
>       if (ret)
>               goto autoconf_fail;
>  
> +     pr_info("Number of LUNs=%d\n", fsg->common->nluns);
> +
>       return 0;
>  
>  autoconf_fail:
> 
> 
> 
> Is this something that needs fixing or am I misunderstanding how
> configfs usb mass storage is supposed to work or be configured ?

it certainly needs to be fixed.

-- 
balbi

Attachment: signature.asc
Description: Digital signature

Reply via email to