linux.git/drivers/usb/mtu3, branch v6.7

usb: mtu3: Convert to platform remove callback returning void

2023-10-21T10:49:08+00:00

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

The function mtu3_remove() can only return a non-zero value if
ssusb->dr_mode is neiter USB_DR_MODE_PERIPHERAL nor USB_DR_MODE_HOST nor
USB_DR_MODE_OTG. In this case however the probe callback doesn't succeed
and so the remove callback isn't called at all. So the code branch
resulting in this error path could just be dropped were it not for the
compiler choking on "enumeration value 'USB_DR_MODE_UNKNOWN' not handled
in switch [-Werror=switch]". So instead replace this code path by a
WARN_ON and then mtu3_remove() be converted to return void trivially.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20231020151537.2202675-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: Explicitly include correct DT includes

2023-07-25T16:20:02+00:00

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Acked-by: Herve Codina 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20230718143027.1064731-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: add optional clock xhci_ck and frmcnt_ck

2023-04-20T09:17:05+00:00

Add optional clock 'xhci_ck' which is usually the same as sys_ck, but
some SoC use two separated clocks when the controller supports dual
role mode;
Add optional clock 'frmcnt_ck' used on 4nm or advanced process SoC.

Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-7-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: expose role-switch control to userspace

2023-04-20T09:17:05+00:00

The allow_userspace_control flag enables manual role switch from userspace,
turn this feature on like several other USB DRD controller drivers.

Reviewed-by: AngeloGioacchino Del Regno 
Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-5-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: unlock @mtu->lock just before giving back request

2023-04-20T09:17:05+00:00

No need unlock @mtu->lock when unmap request, unlock it just before
giving back request, due to we do not lock this spinlock when map
the request.

Reviewed-by: AngeloGioacchino Del Regno 
Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-4-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: fix kernel panic at qmu transfer done irq handler

2023-04-20T09:17:05+00:00

When handle qmu transfer irq, it will unlock @mtu->lock before give back
request, if another thread handle disconnect event at the same time, and
try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu
irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before
handling it.

e.g.
qmu done irq on cpu0                 thread running on cpu1

qmu_done_tx()
  handle gpd [0]
    mtu3_requ_complete()        mtu3_gadget_ep_disable()
      unlock @mtu->lock
        give back request         lock @mtu->lock
                                    mtu3_ep_disable()
                                      mtu3_gpd_ring_free()
                                   unlock @mtu->lock
      lock @mtu->lock
    get next gpd [1]

[1]: goto [0] to handle next gpd, and next gpd may be NULL.

Fixes: 48e0d3735aa5 ("usb: mtu3: supports new QMU format")
Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-3-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: use boolean return value

2023-04-20T09:17:05+00:00

Prefer to use boolean value due to gpd_ring_empty() return true or false.
See "16) Function return values and names" in coding-style.rst

Reviewed-by: AngeloGioacchino Del Regno 
Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: give back request when rx error happens

2023-04-20T09:17:05+00:00

When the Rx enconnter errors, currently, only print error logs, that
may cause class driver's RX halt, shall give back the request with
error status meanwhile.

Signed-off-by: Chunfeng Yun 
Link: https://lore.kernel.org/r/20230417025203.18097-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman

usb: Add explicit of.h of_platform.h include

2023-04-20T08:12:29+00:00

Several USB drivers use of_platform_* functions which are declared in
of_platform.h. of_platform.h gets implicitly included by of_device.h,
but that is going to be removed soon. Nothing else depends on of_device.h
so it can be dropped.

Acked-by: Thinh Nguyen 
Acked-by: Chunfeng Yun 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20230410232639.1561152-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman

usb: mtu3: fix the failure of qmu stop

2023-01-19T13:12:08+00:00

This happens when do stress test of uvc stream on/off which will
enable/disable endpoints. uvc has four tx requests, and may disable
endpoint between queue tx requests as following:
    enable ep --> start qmu
    queue tx request0
    queue tx request1
    queue tx request2 --> resume qmu
    disable ep --> stop qmu may fail [1]
    queue tx request3 --> will resume qmu, may cause qmu can't work
                          when enable ep next time [2]

[1]: when the tx fifo has some data to transmit, and
    try to stop qmu (stop ep) meanwhile resume qmu (queue tx request),
    it may cause stop qmu timeout, then can be fixed by flushing fifo
    when stop qmu.
[2]: it resumes qmu again, shall stop qmu again.

Signed-off-by: Chunfeng Yun 
Reported-by: Min Guo 
Link: https://lore.kernel.org/r/20230119033322.21426-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman