Instead of *always* dumping raw ctrl bytes, let's decode standard
requests which will make the lives of those debugging DWC3 quite a bit
easier.

Output will now look like so:

irq/34-dwc3-1594  [000] d..1   107.573081: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   107.573694: dwc3_ctrl_req: Set Address(Addr = 01)
irq/34-dwc3-1594  [000] d..1   107.588319: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   107.588816: dwc3_ctrl_req: Get Configuration Descriptor(Index = 0, Length = 9)
irq/34-dwc3-1594  [000] d..1   107.589191: dwc3_ctrl_req: Set Configuration(Config = 3)
irq/34-dwc3-1594  [000] d..1   107.589846: dwc3_ctrl_req: Get BOS Descriptor(Index = 0, Length = 5)
irq/34-dwc3-1594  [000] d..1   107.590146: dwc3_ctrl_req: Get BOS Descriptor(Index = 0, Length = 22)
irq/34-dwc3-1594  [000] d..1   107.590546: dwc3_ctrl_req: Get Configuration Descriptor(Index = 0, Length = 9)
irq/34-dwc3-1594  [000] d..1   107.590840: dwc3_ctrl_req: Get Configuration Descriptor(Index = 0, Length = 69)
irq/34-dwc3-1594  [000] d..1   107.591138: dwc3_ctrl_req: Get Configuration Descriptor(Index = 1, Length = 9)
irq/34-dwc3-1594  [000] d..1   107.591541: dwc3_ctrl_req: Get Configuration Descriptor(Index = 1, Length = 32)
irq/34-dwc3-1594  [000] d..1   107.591834: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   114.701005: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   114.721080: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   114.722709: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   114.728979: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   114.730544: dwc3_ctrl_req: Get Device Qualifier Descriptor(Index = 0, Length = 10)
irq/34-dwc3-1594  [000] d..1   115.776018: dwc3_ctrl_req: Get Configuration Descriptor(Index = 0, Length = 9)
irq/34-dwc3-1594  [000] d..1   115.776760: dwc3_ctrl_req: Set Configuration(Config = 0)
irq/34-dwc3-1594  [000] d..1   115.777676: dwc3_ctrl_req: Get Configuration(Length = 1)
irq/34-dwc3-1594  [000] d..1   115.924797: dwc3_ctrl_req: Get Device Descriptor(Index = 0, Length = 18)
irq/34-dwc3-1594  [000] d..1   115.929025: dwc3_ctrl_req: Get String Descriptor(Index = 0, Length = 500)
irq/34-dwc3-1594  [000] d..1   115.929566: dwc3_ctrl_req: Get String Descriptor(Index = 1, Length = 500)
irq/34-dwc3-1594  [000] d..1   115.930911: dwc3_ctrl_req: Get String Descriptor(Index = 0, Length = 500)
irq/34-dwc3-1594  [000] d..1   115.931528: dwc3_ctrl_req: Get String Descriptor(Index = 2, Length = 500)
irq/34-dwc3-1594  [000] d..1   115.932950: dwc3_ctrl_req: Get String Descriptor(Index = 0, Length = 500)
irq/34-dwc3-1594  [000] d..1   115.933533: dwc3_ctrl_req: Get String Descriptor(Index = 3, Length = 500)

Note that Class and Vendor requests won't be decoded for obvious
reasons. Those will be printed as a raw sequence of bytes.

This patch has been tested against a normal host (both Linux and
Windows) and USB30CV Chapter 9 tests.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Instead, we can require caller to pass a buffer for the function to
use. This cleans things quite a bit.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

That helper can be used from our tracepoint interface with very minor
edits. Let's do so.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Finally get rid of dwc3_trace() hack. If any other
message is truly needed, we should add proper
tracepoints for them instead of hacking around with
dwc3_trace() or similar.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

We don't need dwc3_trace() unless we're building a
kernel with CONFIG_FTRACE. This patch reduces
dwc3.ko text size a bit while also removing overhead
of dwc3_trace() calls.

   text    data     bss     dec     hex filename
  50796     581       0   51377    c8b1 drivers/usb/dwc3/dwc3.o
  43961     581       0   44542    adfe drivers/usb/dwc3/dwc3.o.patched

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

With this extra piece of information, it will be
easier to find mismatches between driver and HW.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

We will be using dwc3_ep0_state_string() from within
our tracepoints, so we need to move that helper to
debug.h in order for it to be accessible.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

DWC3 can tell us which phase of a setup transfer
we're getting into. Let's decode it from the event
to make it easier to debug.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

There was a typo when generating endpoint name which
would be very confusing when debugging. Fix it.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Just like we did for endpoint commands, let's have a
single trace output for the command and its
status. This will improve trace readability

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>