On Thu, Jun 29, 2017 at 05:16:41PM +0200, Greg KH wrote: > On Mon, Jun 26, 2017 at 02:23:12PM -0700, Luis R. Rodriguez wrote: > > From: Jakub Kicinski <[email protected]> > > > > The firmware cache mechanism serves two purposes, the secondary purpose is > > not well documented nor understood. This fixes a regression with the > > secondary > > purpose of the firmware cache mechanism: batched requests. > > > > The firmware cache is used for: > > > > 1) Addressing races with file lookups during the suspend/resume cycle > > by keeping firmware in memory during the cycle > > > > 2) Batched requests for the same file rely only on work from the first file > > lookup, which keeps the firmware in memory until the last > > release_firmware() > > is called > > > > Batched requests *only* take effect if secondary requests come in prior to > > the > > first user calling release_firmware(). The devres name used for the internal > > firmware cache is used as a hint other pending requests are ongoing, the > > firmware buffer data is kept in memory until the last user of the buffer > > calls release_firmware(), therefore serializing requests and delaying the > > release until all requests are done. > > > > Batched requests wait for a wakup or signal (we only accept SIGKILL now) so > > we > > can rely on the first file fetch to write to the pending secondary requests. > > Commit 5b029624948d ("firmware: do not use fw_lock for fw_state protection") > > ported the firmware API to use swait, and in doing so failed to convert > > complete_all() to swake_up_all() -- it used swake_up(), loosing the ability > > for *some* batched requests to take effect. > > > > Without this fix it has been reported plugging in two Intel 6260 Wifi cards > > on a system will end up enumerating the two devices only 50% of the time > > [0]. The ported swake_up() should have actually two devices, however, > > *if more than two cards are used* the swake_up() would not suffice. This > > change is only part of the required fixes for batched requests. Subsequent > > fixes will follow. > > > > This particular change should fix the cases where more than three requests > > with the same firmware name is used, otherwise batched requests will wait > > for > > MAX_SCHEDULE_TIMEOUT and just timeout eventually. > > > > [0] https://bugzilla.kernel.org/show_bug.cgi?id=195477 > > > > Fixes: 5b029624948d ("firmware: do not use fw_lock for fw_state protection") > > CC: <[email protected]> [4.10+] > > Cc: Ming Lei <[email protected]> > > Signed-off-by: Jakub Kicinski <[email protected]> > > [mcgrof: expanded on impact on commit log] > > Signed-off-by: Luis R. Rodriguez <[email protected]> > > --- > > > > Greg, I think it would make sense to queue this in after the signal stable > > fixes [1]. > > As I just dropped them, can you redo this based on Linus's tree now?
Oh nevermind, it does apply to that tree now. Wait, what am I supposed to do here? confused, greg k-h
