This totally reimplements the microframe scheduler in dwc2 to attempt to
handle periodic splits properly. The old code didn't even try, so this
was a significant effort since periodic splits are one of the most
complicated things in USB.
I've attempted to keep the old "don't use the microframe" schduler
around for now, but not sure it's needed. It has also only been lightly
tested.
I think it's pretty certain that this scheduler isn't perfect and might
have some bugs, but it seems much better than what was there before.
With this change my stressful USB test (USB webcam + USB audio + some
keyboards) crackles less.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
The dwc2 scheduler (contained in hcd_queue.c) was a bit confusing in the
way it initted / kept track of which frames a QH was going to be active
in. Let's clean things up a little bit in preparation for a rewrite of
the microframe scheduler.
Specifically:
* Old code would pick a frame number in dwc2_qh_init() and would try to
pick it "in a slightly future (micro)frame". As far as I can tell the
reason for this was that there was a delay between dwc2_qh_init() and
when we actually wanted to dwc2_hcd_qh_add(). ...but apparently this
attempt to be slightly in the future wasn't enough because
dwc2_hcd_qh_add() then had code to reset things if the frame _wasn't_
in the future. There's no reason not to just pick the frame later.
For non-periodic QH we now pick the frame in dwc2_hcd_qh_add(). For
periodic QH we pick the frame at dwc2_schedule_periodic() time.
* The old "dwc2_qh_init() actually assigned to "hsotg->frame_number".
This doesn't seem like a great idea since that variable is supposed to
be used to keep track of which SOF the interrupt handler has seen.
Let's be clean: anyone who wants the current frame number (instead of
the one as of the last interrupt) should ask for it.
* The old code wasn't terribly consistent about trying to use the frame
that the microframe scheduler assigned to it. In
dwc2_sched_periodic_split() when it was scheduling the first frame it
always "ORed" in 0x7 (!). Since the frame goes on the wire 1 uFrame
after next_active_frame it meant that the SSPLIT would always try for
uFrame 0 and the transaction would happen on the low speed bus during
uFrame 1. This is irregardless of what the microframe scheduler
said.
* The old code assumed it would get called to schedule the next in a
periodic split very quickly. That is if next_active_frame was
0 (transfer on wire in uFrame 1) it assumed it was getting called to
schedule the next uFrame during uFrame 1 too (so it could queue
something up for uFrame 2). It should be possible to actually queue
something up for uFrame 2 while in uFrame 2 (AKA queue up ASAP). To
do this, code needs to look at the previously scheduled frame when
deciding when to next be active, not look at the current frame number.
* If there was no microframe scheduler, the old code would check for
whether we should be active using "qh->next_active_frame ==
frame_number". This seemed like a race waiting to happen. ...plus
there's no way that you wouldn't want to schedule if next_active_frame
was actually less than frame number.
Note that this change doesn't make 100% sense on its own since it's
expecting some sanity in the frame numbers assigned by the microframe
scheduler and (as per the future patch which rewries it) I think that
the current microframe scheduler is quite insane. However, it seems
like splitting this up from the microframe scheduler patch makes things
into smaller chunks and hopefully adds to clarity rather than reduces
it. The two patches could certainly be squashed. Not that in the very
least, I don't see any obvious bad behavior introduced with just this
patch.
I've attempted to keep the config parameter to disable the microframe
scheduler in tact in this change, though I'm not sure it's worth it.
Obviously the code is touched a lot so it's possible I regressed
something when the microframe scheduler is disabled, though I did some
basic testing and it seemed to work OK. I'm still not 100% sure why you
wouldn't want the microframe scheduler (presuming it works), so maybe a
future patch (or a future version of this patch?) could remove that
parameter.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
This no-op change just does some renames to simplify a future patch.
1. The "interval" field is renamed to "host_interval" to make it more
obvious that this interval may be 8 times the interval that the
device sees (if we're doing split transactions). A future patch will
also add the "device_interval" field.
2. The "usecs" field is renamed to "host_us" again to make it more
obvious that this is the time for the transaction as seen by the
host. For split transactions the device may see a much longer
transaction time. A future patch will also add "device_us".
3. The "sched_frame" field is renamed to "next_active_frame". The name
"sched_frame" kept confusing me because it felt like something more
permament (the QH's reservation or something). The name
"next_active_frame" makes it more obvious that this field is
constantly changing.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
We'd like to be able to use HCD_BH in order to speed up the dwc2 host
interrupt handler quite a bit. However, according to the kernel doc for
usb_submit_urb() (specifically the part about "Reserved Bandwidth
Transfers"), we need to keep a reservation active as long as a device
driver keeps submitting. That was easy to do when we gave back the URB
in the interrupt context: we just looked at when our queue was empty and
released the reserved bandwidth then. ...but now we need a little more
complexity.
We'll follow EHCI's lead in commit 9118f9eb4f ("USB: EHCI: improve
interrupt qh unlink") and add a 5ms delay. Since we don't have a whole
timer infrastructure in dwc2, we'll just add a timer per QH. The
overhead for this is very small.
Note that the dwc2 scheduler is pretty broken (see future patches to fix
it). This patch attempts to replicate all old behavior and just add the
proper delay.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
In preparation for future changes to the scheduler let's add some
tracing that makes it easy for us to see what's happening. By default
this tracing will be off.
By changing "core.h" you can easily trace to ftrace, the console, or
nowhere.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
We're supposed to keep outstanding splits in order. Keep track of a
list of the order of splits and process channel interrupts in that
order.
Without this change and the following setup:
* Rockchip rk3288 Chromebook, using port ff540000
-> Pluggable 7-port Hub with Charging (powered)
-> Microsoft Wireless Keyboard 2000 in port 1.
-> Das Keyboard in port 2.
...I find that I get dropped keys on the Microsoft keyboard (I'm sure
there are other combinations that fail, but this documents my test).
Specifically I've been typing "hahahahahahaha" on the keyboard and often
see keys dropped or repeated.
After this change the above setup works properly. This patch is based
on a previous patch proposed by Yunzhi Li ("usb: dwc2: hcd: fix periodic
transfer schedule sequence")
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Yunzhi Li <lyz@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
All other host controllers who want aligned buffers for DMA do it a
certain way. Let's do that too instead of working behind the USB core's
back. This makes our interrupt handler not take forever and also rips
out a lot of code, simplifying things a bunch.
This also has the side effect of removing the 65535 max transfer size
limit.
NOTE: The actual code to allocate the aligned buffers is ripped almost
completely from the tegra EHCI driver. At some point in the future we
may want to add this functionality to the USB core to share more code
everywhere.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: John Youn <johnyoun@synopsys.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: John Youn <johnyoun@synopsys.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
These functions should go in core.h where they can be called from core,
device, or host.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Use Streaming DMA mappings to handle cache coherency of frame list and
descriptor list. Cache are always flushed before controller access it
or before cpu access it.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Isochronous descriptor is currently programmed for the frame
after the last descriptor was programmed.
If the last descriptor frame underrun, then current descriptor must
take this into account and must be programmed on the current frame + 1.
This overrun usually happens when system is loaded and dwc2 can't init
descriptor list in time.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This function allow comparing frame index used for
descriptor list which has 64 entries.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch switches calls to readl/writel to their
dwc2_readl/dwc2_writel equivalents which preserve platform endianness.
This patch is necessary to access dwc2 registers correctly on big-endian
systems such as the mips based SoCs made by Lantiq. Then dwc2 can be
used to replace ifx-hcd driver for Lantiq platforms found e.g. in
OpenWrt.
The patch was autogenerated with the following commands:
$EDITOR core.h
sed -i "s/\<readl\>/dwc2_readl/g" *.c hcd.h hw.h
sed -i "s/\<writel\>/dwc2_writel/g" *.c hcd.h hw.h
Some files were then hand-edited to fix checkpatch.pl warnings about
too long lines.
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
To avoid sleep while atomic bugs, allocate qh before calling
dwc2_hcd_urb_enqueue. qh pointer can be used directly now instead of
passing ep->hcpriv as double pointer.
Acked-by: John Youn <johnyoun@synopsys.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
So the parameters can be used in both host and gadget modes.
Also consolidate param functions in the core.h
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch will aggregate the probing of gadget/hcd driver into platform.c.
The gadget probe funtion is converted into gadget_init that is now only
responsible for gadget only initialization. All the gadget resources are now
handled by platform.c
Since the host workqueue will not get initialized if the driver is configured
for peripheral mode only. Thus we need to check for wq_otg before calling
queue_work().
Also, we move spin_lock_init to common location for both host and gadget that
is either in platform.c or pci.c.
We also move suspend/resume code to common platform code.
Lastly, move the "samsung,s3c6400-hsotg" binding into dwc2_of_match_table.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
The driver's handling of DMA buffers for non-aligned transfers
was kind of nuts. For IN transfers, it left the URB DMA buffer
mapped until the transfer completed, then synced it, copied the
data from the bounce buffer, then synced it again.
Instead of that, just call usb_hcd_unmap_urb_for_dma() to unmap
the buffer before starting the transfer. Then no syncing is
required when doing the copy. This should also allow handling of
other types of mappings besides just dma_map_single() ones.
Also reduce the size of the bounce buffer allocation for Isoc
endpoints to 3K, since that's the largest possible transfer size.
Tested on Raspberry Pi and Altera SOCFPGA.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DWC2 driver should now be in good enough shape to move out of
staging. I have stress tested it overnight on RPI running mass
storage and Ethernet transfers in parallel, and for several days
on our proprietary PCI-based platform.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
