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usb: dwc2: gadget: Transfer length limit checking for DDMA

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Add dwc2_gadget_get_chain_limit() function and its call in transfer
start routine to correctly estimate one go on transfer size if
descriptor DMA mode is selected.

Signed-off-by: Vahram Aharonyan <vahrama@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Vahram Aharonyan 2016-11-09 19:28:01 -08:00 committed by Felipe Balbi
parent 3a1ec35160
commit cf77b5fb9b
1 changed files with 31 additions and 1 deletions
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32
drivers/usb/dwc2/gadget.c
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@ -601,6 +601,32 @@ static u32 dwc2_hsotg_read_frameno(struct dwc2_hsotg *hsotg)
return dsts;
}
/**
* dwc2_gadget_get_chain_limit - get the maximum data payload value of the
* DMA descriptor chain prepared for specific endpoint
* @hs_ep: The endpoint
*
* Return the maximum data that can be queued in one go on a given endpoint
* depending on its descriptor chain capacity so that transfers that
* are too long can be split.
*/
static unsigned int dwc2_gadget_get_chain_limit(struct dwc2_hsotg_ep *hs_ep)
{
int is_isoc = hs_ep->isochronous;
unsigned int maxsize;
if (is_isoc)
maxsize = hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_LIMIT :
DEV_DMA_ISOC_RX_NBYTES_LIMIT;
else
maxsize = DEV_DMA_NBYTES_LIMIT;
/* Above size of one descriptor was chosen, multiple it */
maxsize *= MAX_DMA_DESC_NUM_GENERIC;
return maxsize;
}
/**
* dwc2_hsotg_start_req - start a USB request from an endpoint's queue
* @hsotg: The controller state.
@ -659,7 +685,11 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg,
dev_dbg(hsotg->dev, "ureq->length:%d ureq->actual:%d\n",
ureq->length, ureq->actual);
maxreq = get_ep_limit(hs_ep);
if (!using_desc_dma(hsotg))
maxreq = get_ep_limit(hs_ep);
else
maxreq = dwc2_gadget_get_chain_limit(hs_ep);
if (length > maxreq) {
int round = maxreq % hs_ep->ep.maxpacket;