Insufficient memory reserved for xfer->dma_page_ptr?

[Aman Sawrup]

Hi Hans,

If I understand correctly, I need to set bufsize in struct usb_config as 
follows:

	[UMASS_T_BBB_DATA_READ] = {
		.type = UE_BULK,
		.endpoint = UE_ADDR_ANY,
		.direction = UE_DIR_IN,
		.frames = 128,
		.bufsize = UMASS_BULK_SIZE * 128,
		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1, UMASS_USB_FLAGS},
		.callback = &umass_t_bbb_data_read_callback,
		.timeout = 0,	/* overwritten later */
	},

Thanks
Aman

On 02/20/2013 02:36 AM, Hans Petter Selasky wrote:
> On Tuesday 19 February 2013 23:26:19 Aman Sawrup wrote:
>> I believe the amount of memory reserved needs to be much higher.  For
>> example, if sizeof(struct usb_page) is 16 bytes, then for n_frbuffers of
>> 128 and parm->bufsize of 131072, we need the following amount of memory
>> reserved:
>>
>> parm->bufsize / USB_PAGE_SIZE * n_frbuffers * sizeof(struct usb_page)
>> = 131072 / 4096 * 128 * 16
>> = 65536
> Hi,
>
> The parm->bufsize is shared for all frbuffers, so the formula should be
> correct. In your computation you assume that parm->bufsize gives the maximum
> for each frbuffer. That is not the case.
>
> That means, when you configure bufsize, you must not exceed that size as a
> total when setting up frames. This include all transfer types. I think there
> are asserts for that so you should get a panic fairly quickly.
>
> --HPS