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usb: dwc3: ep0: handle non maxpacket aligned transfers > 512

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Use chained TRB mechanism to handle non maxpacket aligned transfers
greater than bounce buffer size. With this the first TRB will be programmed
to receive 'ALIGN(ur->length - maxp, maxp)' data and the second TRB
will be programmed to receive the remaining data using bounce buffer.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Kishon Vijay Abraham I 2015-07-27 12:25:32 +05:30 committed by Felipe Balbi
parent 2abd9d5fa6
commit c0bd5456a4
1 changed files with 28 additions and 14 deletions
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42
drivers/usb/dwc3/ep0.c
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@ -834,13 +834,26 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
maxp = ep0->endpoint.maxpacket;
if (dwc->ep0_bounced) {
/*
* Handle the first TRB before handling the bounce buffer if
* the request length is greater than the bounce buffer size
*/
if (ur->length > DWC3_EP0_BOUNCE_SIZE) {
transfer_size = ALIGN(ur->length - maxp, maxp);
transferred = transfer_size - length;
buf = (u8 *)buf + transferred;
ur->actual += transferred;
remaining_ur_length -= transferred;
trb++;
length = trb->size & DWC3_TRB_SIZE_MASK;
ep0->free_slot = 0;
}
transfer_size = roundup((ur->length - transfer_size),
maxp);
/* Maximum of DWC3_EP0_BOUNCE_SIZE can only be received */
if (transfer_size > DWC3_EP0_BOUNCE_SIZE)
transfer_size = DWC3_EP0_BOUNCE_SIZE;
transferred = min_t(u32, remaining_ur_length,
transfer_size - length);
memcpy(buf, dwc->ep0_bounce, transferred);
@ -963,21 +976,22 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
}
maxpacket = dep->endpoint.maxpacket;
if (req->request.length > DWC3_EP0_BOUNCE_SIZE) {
transfer_size = ALIGN(req->request.length - maxpacket,
maxpacket);
ret = dwc3_ep0_start_trans(dwc, dep->number,
req->request.dma,
transfer_size,
DWC3_TRBCTL_CONTROL_DATA,
true);
}
transfer_size = roundup((req->request.length - transfer_size),
maxpacket);
if (transfer_size > DWC3_EP0_BOUNCE_SIZE) {
dev_WARN(dwc->dev, "bounce buf can't handle req len\n");
transfer_size = DWC3_EP0_BOUNCE_SIZE;
}
dwc->ep0_bounced = true;
/*
* REVISIT in case request length is bigger than
* DWC3_EP0_BOUNCE_SIZE we will need two chained
* TRBs to handle the transfer.
*/
ret = dwc3_ep0_start_trans(dwc, dep->number,
dwc->ep0_bounce_addr, transfer_size,
DWC3_TRBCTL_CONTROL_DATA, false);