From: John Stultz <john.stultz@linaro.org>
To: Michal Nazarewicz <mina86@mina86.com>
Cc: Chen Yu <chenyu56@huawei.com>,
Felipe Balbi <felipe.balbi@linux.intel.com>,
Greg KH <gregkh@linuxfoundation.org>,
Biggo Wang <wangbinghui@hisilicon.com>,
Amit Pundir <amit.pundir@linaro.org>,
Guodong Xu <guodong.xu@linaro.org>,
lkml <linux-kernel@vger.kernel.org>,
linux-usb@vger.kernel.org
Subject: Re: [PATCH 2/2] usb: gadget: f_fs: stop sleeping in ffs_func_eps_disable
Date: Mon, 3 Oct 2016 17:26:06 -0700 [thread overview]
Message-ID: <CALAqxLXAik6KJVJB7R7irME4c8tKREvnh2z6s7wNBuJpkkuhOw@mail.gmail.com> (raw)
In-Reply-To: <1475539654-31945-2-git-send-email-mina86@mina86.com>
On Mon, Oct 3, 2016 at 5:07 PM, Michal Nazarewicz <mina86@mina86.com> wrote:
> ffs_func_eps_disable is called from atomic context so it cannot sleep
> thus cannot grab a mutex. Change the handling of epfile->read_buffer
> to use non-sleeping synchronisation method.
>
> Reported-by: Chen Yu <chenyu56@huawei.com>
> Signed-off-by: Michał Nazarewicz <mina86@mina86.com>
> Fixes: 9353afbbfa7b ("buffer data from ‘oversized’ OUT requests")
> Tested-by: Chen Yu <chenyu56@huawei.com>
> ---
> drivers/usb/gadget/function/f_fs.c | 109 +++++++++++++++++++++++++++++++------
> 1 file changed, 93 insertions(+), 16 deletions(-)
>
> Compared to the previous version:
> • this one has a bit more comments (I feel like it’s a bad sign that
> this needs so much documentation);
> • ffs_epfile_realese sets read_buffer to READ_BUFFER_DROP (which
> doesn’t matter since on entry __ffs_epfile_read_buffered behaves
> the same way when read_buffer is NULL or READ_BUFFER_DROP); and
> • __ffs_epfile_read_data will drop the temporary data if read_buffer
> is READ_BUFFER_DROP (which may happen if ep is disabled between ep
> request finishes and data is copied to user space).
>
> Chen, John, if you could test this version as well, that would be
> swell.
for both patches:
Tested-by: John Stultz <john.stultz@linaro.org>
Thanks so much for these!
-john
next prev parent reply other threads:[~2016-10-04 0:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-27 9:44 BUG: scheduling while atomic in f_fs when gadget remove driver Chen Yu
2016-09-27 10:01 ` Felipe Balbi
2016-09-28 9:47 ` Chen Yu
2016-09-28 16:31 ` Michal Nazarewicz
2016-09-28 21:38 ` Michal Nazarewicz
2016-09-30 1:49 ` Chen Yu
2016-10-03 19:19 ` John Stultz
2016-10-03 20:07 ` Michal Nazarewicz
2016-10-03 20:16 ` John Stultz
2016-10-03 23:36 ` John Stultz
2016-10-04 0:07 ` [PATCH 1/2] usb: gadget: f_fs: edit epfile->ep under lock Michal Nazarewicz
2016-10-04 0:07 ` [PATCH 2/2] usb: gadget: f_fs: stop sleeping in ffs_func_eps_disable Michal Nazarewicz
2016-10-04 0:26 ` John Stultz [this message]
2016-10-08 6:52 ` Chen Yu
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