usb: gadget: dummy_hcd: add sg support
This patch adds sg support to dummy_hcd. It seems that uas is not able
to work with a hcd which does not support sg only based transfers.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index 61e893a..4973778 100644
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -39,6 +39,7 @@
#include <linux/usb.h>
#include <linux/usb/gadget.h>
#include <linux/usb/hcd.h>
+#include <linux/scatterlist.h>
#include <asm/byteorder.h>
#include <asm/io.h>
@@ -147,6 +148,8 @@
struct urbp {
struct urb *urb;
struct list_head urbp_list;
+ struct sg_mapping_iter miter;
+ u32 miter_started;
};
@@ -1077,13 +1080,11 @@
unsigned long flags;
int rc;
- if (!urb->transfer_buffer && urb->transfer_buffer_length)
- return -EINVAL;
-
urbp = kmalloc (sizeof *urbp, mem_flags);
if (!urbp)
return -ENOMEM;
urbp->urb = urb;
+ urbp->miter_started = 0;
dum_hcd = hcd_to_dummy_hcd(hcd);
spin_lock_irqsave(&dum_hcd->dum->lock, flags);
@@ -1137,17 +1138,66 @@
u32 len)
{
void *ubuf, *rbuf;
+ struct urbp *urbp = urb->hcpriv;
int to_host;
+ struct sg_mapping_iter *miter = &urbp->miter;
+ u32 trans = 0;
+ u32 this_sg;
+ bool next_sg;
to_host = usb_pipein(urb->pipe);
rbuf = req->req.buf + req->req.actual;
- ubuf = urb->transfer_buffer + urb->actual_length;
- if (to_host)
- memcpy(ubuf, rbuf, len);
- else
- memcpy(rbuf, ubuf, len);
- return len;
+ if (!urb->num_sgs) {
+ ubuf = urb->transfer_buffer + urb->actual_length;
+ if (to_host)
+ memcpy(ubuf, rbuf, len);
+ else
+ memcpy(rbuf, ubuf, len);
+ return len;
+ }
+
+ if (!urbp->miter_started) {
+ u32 flags = SG_MITER_ATOMIC;
+
+ if (to_host)
+ flags |= SG_MITER_TO_SG;
+ else
+ flags |= SG_MITER_FROM_SG;
+
+ sg_miter_start(miter, urb->sg, urb->num_sgs, flags);
+ urbp->miter_started = 1;
+ }
+ next_sg = sg_miter_next(miter);
+ if (next_sg == false) {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ do {
+ ubuf = miter->addr;
+ this_sg = min_t(u32, len, miter->length);
+ miter->consumed = this_sg;
+ trans += this_sg;
+
+ if (to_host)
+ memcpy(ubuf, rbuf, this_sg);
+ else
+ memcpy(rbuf, ubuf, this_sg);
+ len -= this_sg;
+
+ if (!len)
+ break;
+ next_sg = sg_miter_next(miter);
+ if (next_sg == false) {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ rbuf += this_sg;
+ } while (1);
+
+ sg_miter_stop(miter);
+ return trans;
}
/* transfer up to a frame's worth; caller must own lock */
@@ -1198,10 +1248,13 @@
len = dummy_perform_transfer(urb, req, len);
ep->last_io = jiffies;
-
- limit -= len;
- urb->actual_length += len;
- req->req.actual += len;
+ if (len < 0) {
+ req->req.status = len;
+ } else {
+ limit -= len;
+ urb->actual_length += len;
+ req->req.actual += len;
+ }
}
/* short packets terminate, maybe with overflow/underflow.
@@ -2212,6 +2265,7 @@
static int dummy_setup(struct usb_hcd *hcd)
{
+ hcd->self.sg_tablesize = ~0;
if (usb_hcd_is_primary_hcd(hcd)) {
the_controller.hs_hcd = hcd_to_dummy_hcd(hcd);
the_controller.hs_hcd->dum = &the_controller;