linux/drivers/usb/dwc2
Douglas Anderson 9ed04d9761 usb: dwc2: host: Properly set the HFIR
According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

In case you didn't spot it, the difference is the "- 1".

Let's add the "- 1" to match the newest user manual.  It's presumed that
the "- 1" should have always been there and that this was always a
documentation error.  If some hardware needs the "- 1" and other
hardware doesn't, we'll have to add a configuration parameter for it in
the future.

I checked things before and after this patch on rk3288 using a Total
Phase Beagle 5000 analyzer.

Before this patch, a low speed mouse shows constant Frame Timing Jitter
errors.  After this patch errors have gone away.

Before this patch SOF packets move forward about 1 us per 4 ms.  After
this patch the SOF packets move backward about 1 us per 255 ms.  Some
specific SOF timestamps from the analyzer are below.

Before:
  6.603.790
  6.603.916
  6.604.041
  6.604.166
  ...
  6.607.541
  6.607.667
  6.607.792
  6.607.917
  ...
  6.611.417
  6.611.543
  6.611.668
  6.611.793

After:
  6.215.159
  6.215.284
  6.215.408
  6.215.533
  6.215.658
  ...
  6.470.658
  6.470.783
  6.470.907
  ...
  6.726.032
  6.726.157
  6.725.281
  6.725.406

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
2016-03-04 15:14:42 +02:00
..
core_intr.c usb: dwc2: host: Clear interrupts before handling them 2015-12-15 09:12:41 -06:00
core.c usb: dwc2: host: Properly set the HFIR 2016-03-04 15:14:42 +02:00
core.h usb: dwc2: host: Add scheduler tracing 2016-03-04 15:14:41 +02:00
debug.h usb: dwc2: move debugfs code to a separate file 2015-04-29 15:18:25 -05:00
debugfs.c usb: dwc2: Use platform endianness when accessing registers 2015-09-27 10:54:31 -05:00
gadget.c usb: dwc2: gadget: Repair DSTS register decoding 2015-12-22 12:03:05 -06:00
hcd_ddma.c usb: dwc2: host: Always add to the tail of queues 2016-03-04 15:14:40 +02:00
hcd_intr.c usb: dwc2: host: Add scheduler tracing 2016-03-04 15:14:41 +02:00
hcd_queue.c usb: dwc2: host: Add a delay before releasing periodic bandwidth 2016-03-04 15:14:41 +02:00
hcd.c usb: dwc2: host: Giveback URB in tasklet context 2016-03-04 15:14:41 +02:00
hcd.h usb: dwc2: host: Add a delay before releasing periodic bandwidth 2016-03-04 15:14:41 +02:00
hw.h usb: dwc2: host: fix descriptor list address masking 2015-12-15 09:12:41 -06:00
Kconfig usb: dwc2: USB_DWC2 should depend on HAS_DMA 2016-02-20 20:23:02 -08:00
Makefile usb: dwc2: remove dwc2_platform.ko 2015-04-29 15:20:11 -05:00
pci.c usb: dwc2: pci: Add device mode to the dwc2-pci driver 2015-03-11 15:08:17 -05:00
platform.c usb: dwc2: host: Set host_rx_fifo_size to 525 for rk3066 2016-03-04 15:14:39 +02:00