On 06/15/2014 10:42 AM, Yang,Wei wrote:
Its v4, sorry for missing it in subject.
Alan, How about this version?
Cheers
Wei
Regards
Wei
On 06/15/2014 10:40 AM, Wei.Yang@xxxxxxxxxxxxx wrote:
From: Yang Wei <Wei.Yang@xxxxxxxxxxxxx>
While loading g_mass_storage module, the following warning
is triggered.
WARNING: at drivers/usb/gadget/composite.c:
usb_composite_setup_continue: Unexpected call
Modules linked in: fat vfat minix nls_cp437 nls_iso8859_1 g_mass_storage
[<800179cc>] (unwind_backtrace+0x0/0x104) from [<80619608>]
(dump_stack+0x20/0x24)
[<80619608>] (dump_stack+0x20/0x24) from [<80025100>]
(warn_slowpath_common+0x64/0x74)
[<80025100>] (warn_slowpath_common+0x64/0x74) from [<800251cc>]
(warn_slowpath_fmt+0x40/0x48)
[<800251cc>] (warn_slowpath_fmt+0x40/0x48) from [<7f047774>]
(usb_composite_setup_continue+0xb4/0xbc [g_mass_storage])
[<7f047774>] (usb_composite_setup_continue+0xb4/0xbc
[g_mass_storage]) from [<7f047ad4>] (handle_exception+0x358/0x3e4
[g_mass_storage])
[<7f047ad4>] (handle_exception+0x358/0x3e4 [g_mass_storage]) from
[<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage])
[<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage]) from
[<8004bc90>] (kthread+0x98/0x9c)
[<8004bc90>] (kthread+0x98/0x9c) from [<8000faec>]
(kernel_thread_exit+0x0/0x8)
The root cause is that the existing code fails to take into
account the possibility that common->new_fsg can change while
do_set_interface() is running, so the value of common->new_fsg
that gets tested after do_set_interface returns needs to be
the same as the value used by do_set_interface.
Signed-off-by: Yang Wei <Wei.Yang@xxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/f_mass_storage.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
Changes in v3 ----> v4
move "new_fsg = common->new_fsg" out of comm->lock protection, and
refine the commit log.
Thanks
Wei
diff --git a/drivers/usb/gadget/f_mass_storage.c
b/drivers/usb/gadget/f_mass_storage.c
index b963939..a7e24c8 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -2342,6 +2342,7 @@ static void handle_exception(struct fsg_common
*common)
struct fsg_buffhd *bh;
enum fsg_state old_state;
struct fsg_lun *curlun;
+ struct fsg_dev *new_fsg;
unsigned int exception_req_tag;
/*
@@ -2460,8 +2461,9 @@ static void handle_exception(struct fsg_common
*common)
break;
case FSG_STATE_CONFIG_CHANGE:
- do_set_interface(common, common->new_fsg);
- if (common->new_fsg)
+ new_fsg = common->new_fsg;
+ do_set_interface(common, new_fsg);
+ if (new_fsg)
usb_composite_setup_continue(common->cdev);
break;
--
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