When STM32F746-DISCO board was being used in (unsupported) USBHost mode,
the communication was unreliable. Our investigation revealed that the
problem lied in redundant IN tokens that the host generated even though
it shouldn't. This could lead to endless high-frequency NAKs being
received from device, which caused watchdog reset as USBHost spent all
time in interrupt handlers.
In our application the clocks frequencies are:
* HCLK = 48 MHz
* APB1 = 6 MHz
* APB2 = 12 MHz
We have captured the raw USB High-Speed traffic using OpenVizsla.
Without this change, when USB MSD device connected to the system
responded to IN with NAK, there were excessive IN tokens generated about
667 ns after the NAK. With this commit the IN tokens are generated no
sooner than 10 us after the NAK.
The high frequency of the IN/NAK pairs is not the biggest problem.
The biggest problem is that the USB Host did continue to send the IN token
after DATA and ACK packets were received from device - *without* any request
from upper layer (USB MSD).
The USB MSD devices won't have extra data available on Bulk IN endpoint
after the expected data was received by Host. In such case IN/NAK cycle
time is only houndreds of nanoseconds, the MCU has no time for anything else.
The problem manifested not only on Bulk endpoints, but also during
Control transfers. Example correct scenario (when this fix is applied):
* SETUP stage
* SETUP [host -> address 0 endpoint 0]
* DATA0 [80 06 00 01 00 00 08 00] [CRC16: EB 94]
* ACK
* DATA stage
* IN
* NAK
... the IN/NAK repeated multiple time until device was ready
* IN
* DATA1 [12 01 10 02 00 00 00 40] [CRC16: 55 41]
* ACK
* STATUS stage
* OUT
* DATA1 ZLP
* ACK
Without this commit, in DATA stage, after the ACK was received, the host
did send extra IN to which device responded with STALL. On bus it was:
* DATA stage
...
* IN
* DATA1 [12 01 10 02 00 00 00 40] [CRC16: 55 41]
* IN
* STALL
* IN
* STALL
* STATUS stage
* OUT
* DATA1 ZLP
* STALL
In the fault case the next SETUP was sent only after 510 ms, which
indicates timeout in upper layer.
With this commit the next SETUP is sent 120 us after the STATUS stage ACK.
Compile: stm32f7xx_hal_pcd.c
../targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c: In function 'PCD_WriteEmptyTxFifo':
../targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c:1310:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if (len > ep->maxpacket)
^
../targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c:1325:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if (len > ep->maxpacket)
^
Pending official update from STM, add memory barriers to the Ethernet
HAL code for the STM32F7xx family.
Cortex-M7 has a merging write buffer that is not automatically flushed
by accesses to devices, so without these DMBs, we sometimes lose synch
with the transmitter.
The DMBs are architecturally needed in every version of this HAL, but
adding just to the STM32F7 version for now to clear test, as the
problem has only been observed on Cortex-M7-based devices.
Fixes#5622.
- default value is the same as before patch
- system_stm32f7xx.c file is copied to family level with all other ST cube files
- specific clock configuration is now in a new file: system_clock.c (target level)
When we want to activate USE_FULL_ASSERT macro in STM32 CUBE, there is a
need to have the assert map to MBED.
The easiest way to have this definition in a single place for all STM32
HAL and LL files using it, is to add a specific header file where the
porting to MBED is done.
Before this patch, many warnings like below were generated
during compilation with ArmCC
[Warning] lwip_ethernet.h@57,0: #3135-D: attribute does not apply to any entity
This happens here as ``--gnu`` option of ArmCC is being used, which
enables the GNU compiler extensions that the ARM compiler supports.
This is solve by adding a extra check on __CCARM .
In case of sequential transmit / receive, there is a need to:
- not use the reload option
- generate a new START on each new transaction
This applies to all HAL supporting the IP version V2.
jeromecoutant
Alexandre Bourdiol
Ireneusz Gaicki
Martin Kojtal
Vincent Veron
bcostm
Marcin Tomczyk
Cruz Monrreal
Paul Thompson
Kevin Bracey
Bartek Szatkowski
adustm
Laurent MEUNIER
Michel Jaouen
Sam Grove
Christopher Haster