starterware / pdk_am437x_1_0_0 & usb_host example

Nick Ager

Hi,

I have AM437x starter kit hardware and have been trying to run the usb_host example from: pdk_am437x_1_0_0\packages\ti\drv\usb\example\usb_host\

After much frustration I've finally got the example to work by adding the extra conditional "retStat == S_PASS" in the do ... while loop in FSShellAppUtilsProcess as

int32_t FSShellAppUtilsProcess(void)
{
    uint32_t spinProcess = TRUE;
    int32_t retStat = E_FAIL;

    do
    {
      .
      .
      .
    } while(TRUE == spinProcess && retStat == S_PASS);

    return retStat;
}

Without the extra conditional, the code was stuck in the loop inside FSShellAppUtilsProcess which meant that USBHCDMain wasn't being called, which referring to - http://processors.wiki.ti.com/index.php/StarterWare_USB

>> In order to complete the enumeration process, the host controller driver also requires that the application periodically call the USBHCDMain() function

So is this a bug in the pdk usb_host sample code or have I misunderstood?

Thanks

Nick

over 8 years ago

0 lding over 8 years ago

TI__Guru* 95265 points

Nick,

We tested the USB host example using a 437X GP EVM in the past without any problem. It can enumerate a USB thumb drive and run some simple command. We use the code as it is without changing it. Can you let us know how do you see the problem so I can try to reproduce?

The wiki information is at http://processors.wiki.ti.com/index.php/Processor_SDK_RTOS_USB the USBHCDMain() is called in a while() loop.

Regarding to "Without the extra conditional, the code was stuck in the loop inside FSShellAppUtilsProcess". There is no real loop inside this function, it is a do .... while(0), how do you get stuck inside this loop?

Regards, Eric

0 Nick Ager over 8 years ago in reply to lding

Prodigy 40 points

Hi Eric,

Thanks for replying.

Perhaps the confusion is that I'm building the "bare metal" USB host example - whereas you mention to the TI RTOS version. In the "bare metal" example the while loop inside FSShellAppUtilsProcess is:

int32_t FSShellAppUtilsProcess(void)
{
    uint32_t spinProcess = TRUE;
    int32_t retStat = E_FAIL;

    do
    {
      .
      .
      .
    } while(TRUE == spinProcess);

    return retStat;
}

I found I needed to add the extra conditional "retStat == S_PASS" to the while loop in FSShellAppUtilsProcess as:

int32_t FSShellAppUtilsProcess(void)
{
    uint32_t spinProcess = TRUE;
    int32_t retStat = E_FAIL;

    do
    {
      .
      .
      .
    } while(TRUE == spinProcess && retStat == S_PASS);

    return retStat;
}

otherwise USBHCDMain wasn't being called

Nick

0 Nick Ager over 8 years ago in reply to Nick Ager

Prodigy 40 points

Hi Eric,

Apologies I realised my problem. I was linking against FSShellAppUtilsProcess in:

pdk_am437x_1_0_0\packages\ti\starterware\examples\example_utils\fs_shell_app_utils.c

rather than:

pdk_am437x_1_0_0\packages\ti\drv\usb\example\shell\fs_shell_app_utils.c

which as you said does indeed have a do ... while(0) loop.

There is yet another implementation of FSShellAppUtilsProcess in:

pdk_am437x_1_0_0\packages\ti\mmcsd\example\fatfs_console\src\fs_shell_app_utils.c

... which again is different.

It would have saved me a lot of time if differing methods could be given different names e.g. FSShellAppUtilsProcessMMCSD, FSShellAppUtilsProcessUSB etc.

</suggestion>

Nick

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