use_dma_chaining module parameter was designed to avoid creating one irq
per package on a group of packages (with the help of the driver's flag
no_interrupt).
Unfortunately, when this parameter is enabled, the driver fails to work
on both net2280 and 3380 chips.
This patch removes this parameter, which was disabled by default.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
drivers/usb/gadget/udc/net2280.c | 147 ++++-----------------------------------
1 file changed, 13 insertions(+), 134 deletions(-)
diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
index d6411e0..08c16ee 100644
--- a/drivers/usb/gadget/udc/net2280.c
+++ b/drivers/usb/gadget/udc/net2280.c
@@ -12,11 +12,7 @@
* the Mass Storage, Serial, and Ethernet/RNDIS gadget drivers
* as well as Gadget Zero and Gadgetfs.
*
- * DMA is enabled by default. Drivers using transfer queues might use
- * DMA chaining to remove IRQ latencies between transfers. (Except when
- * short OUT transfers happen.) Drivers can use the req->no_interrupt
- * hint to completely eliminate some IRQs, if a later IRQ is guaranteed
- * and DMA chaining is enabled.
+ * DMA is enabled by default.
*
* MSI is enabled by default. The legacy IRQ is used if MSI couldn't
* be enabled.
@@ -85,7 +81,6 @@ static const char *const ep_name[] = {
};
/* use_dma -- general goodness, fewer interrupts, less cpu load (vs PIO)
- * use_dma_chaining -- dma descriptor queueing gives even more irq reduction
*
* The net2280 DMA engines are not tightly integrated with their FIFOs;
* not all cases are (yet) handled well in this driver or the silicon.
@@ -93,12 +88,10 @@ static const char *const ep_name[] = {
* These two parameters let you use PIO or more aggressive DMA.
*/
static bool use_dma = true;
-static bool use_dma_chaining;
static bool use_msi = true;
/* "modprobe net2280 use_dma=n" etc */
module_param(use_dma, bool, 0444);
-module_param(use_dma_chaining, bool, 0444);
module_param(use_msi, bool, 0444);
/* mode 0 == ep-{a,b,c,d} 1K fifo each
@@ -202,15 +195,6 @@ net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
/* set speed-dependent max packet; may kick in high bandwidth */
set_max_speed(ep, max);
- /* FIFO lines can't go to different packets. PIO is ok, so
- * use it instead of troublesome (non-bulk) multi-packet DMA.
- */
- if (ep->dma && (max % 4) != 0 && use_dma_chaining) {
- ep_dbg(ep->dev, "%s, no dma for maxpacket %d\n",
- ep->ep.name, ep->ep.maxpacket);
- ep->dma = NULL;
- }
-
/* set type, direction, address; reset fifo counters */
writel(BIT(FIFO_FLUSH), &ep->regs->ep_stat);
tmp = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
@@ -747,8 +731,7 @@ static void fill_dma_desc(struct net2280_ep *ep,
req->valid = valid;
if (valid)
dmacount |= BIT(VALID_BIT);
- if (likely(!req->req.no_interrupt || !use_dma_chaining))
- dmacount |= BIT(DMA_DONE_INTERRUPT_ENABLE);
+ dmacount |= BIT(DMA_DONE_INTERRUPT_ENABLE);
/* td->dmadesc = previously set by caller */
td->dmaaddr = cpu_to_le32 (req->req.dma);
@@ -862,8 +845,7 @@ static void start_dma(struct net2280_ep *ep, struct net2280_request *req)
req->td->dmadesc = cpu_to_le32 (ep->td_dma);
fill_dma_desc(ep, req, 1);
- if (!use_dma_chaining)
- req->td->dmacount |= cpu_to_le32(BIT(END_OF_CHAIN));
+ req->td->dmacount |= cpu_to_le32(BIT(END_OF_CHAIN));
start_queue(ep, tmp, req->td_dma);
}
@@ -1150,64 +1132,12 @@ static void scan_dma_completions(struct net2280_ep *ep)
static void restart_dma(struct net2280_ep *ep)
{
struct net2280_request *req;
- u32 dmactl = dmactl_default;
if (ep->stopped)
return;
req = list_entry(ep->queue.next, struct net2280_request, queue);
- if (!use_dma_chaining) {
- start_dma(ep, req);
- return;
- }
-
- /* the 2280 will be processing the queue unless queue hiccups after
- * the previous transfer:
- * IN: wanted automagic zlp, head doesn't (or vice versa)
- * DMA_FIFO_VALIDATE doesn't init from dma descriptors.
- * OUT: was "usb-short", we must restart.
- */
- if (ep->is_in && !req->valid) {
- struct net2280_request *entry, *prev = NULL;
- int reqmode, done = 0;
-
- ep_dbg(ep->dev, "%s dma hiccup td %p\n", ep->ep.name, req->td);
- ep->in_fifo_validate = likely(req->req.zero ||
- (req->req.length % ep->ep.maxpacket) != 0);
- if (ep->in_fifo_validate)
- dmactl |= BIT(DMA_FIFO_VALIDATE);
- list_for_each_entry(entry, &ep->queue, queue) {
- __le32 dmacount;
-
- if (entry == req)
- continue;
- dmacount = entry->td->dmacount;
- if (!done) {
- reqmode = likely(entry->req.zero ||
- (entry->req.length % ep->ep.maxpacket));
- if (reqmode == ep->in_fifo_validate) {
- entry->valid = 1;
- dmacount |= valid_bit;
- entry->td->dmacount = dmacount;
- prev = entry;
- continue;
- } else {
- /* force a hiccup */
- prev->td->dmacount |= dma_done_ie;
- done = 1;
- }
- }
-
- /* walk the rest of the queue so unlinks behave */
- entry->valid = 0;
- dmacount &= ~valid_bit;
- entry->td->dmacount = dmacount;
- prev = entry;
- }
- }
-
- writel(0, &ep->dma->dmactl);
- start_queue(ep, dmactl, req->td_dma);
+ start_dma(ep, req);
}
static void abort_dma_228x(struct net2280_ep *ep)
@@ -1306,25 +1236,6 @@ static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
done(ep, req, -ECONNRESET);
}
req = NULL;
-
- /* patch up hardware chaining data */
- } else if (ep->dma && use_dma_chaining) {
- if (req->queue.prev == ep->queue.next) {
- writel(le32_to_cpu(req->td->dmadesc),
- &ep->dma->dmadesc);
- if (req->td->dmacount & dma_done_ie)
- writel(readl(&ep->dma->dmacount) |
- le32_to_cpu(dma_done_ie),
- &ep->dma->dmacount);
- } else {
- struct net2280_request *prev;
-
- prev = list_entry(req->queue.prev,
- struct net2280_request, queue);
- prev->td->dmadesc = req->td->dmadesc;
- if (req->td->dmacount & dma_done_ie)
- prev->td->dmacount |= dma_done_ie;
- }
}
if (req)
@@ -1609,9 +1520,7 @@ static ssize_t registers_show(struct device *_dev,
"pci irqenb0 %02x irqenb1 %08x "
"irqstat0 %04x irqstat1 %08x\n",
driver_name, dev->chiprev,
- use_dma
- ? (use_dma_chaining ? "chaining" : "enabled")
- : "disabled",
+ use_dma ? "enabled" : "disabled",
readl(&dev->regs->devinit),
readl(&dev->regs->fifoctl),
s,
@@ -3423,17 +3332,12 @@ static void handle_stat1_irqs(struct net2280 *dev, u32 stat)
continue;
}
- /* chaining should stop on abort, short OUT from fifo,
- * or (stat0 codepath) short OUT transfer.
- */
- if (!use_dma_chaining) {
- if (!(tmp & BIT(DMA_TRANSACTION_DONE_INTERRUPT))) {
- ep_dbg(ep->dev, "%s no xact done? %08x\n",
- ep->ep.name, tmp);
- continue;
- }
- stop_dma(ep->dma);
+ if (!(tmp & BIT(DMA_TRANSACTION_DONE_INTERRUPT))) {
+ ep_dbg(ep->dev, "%s no xact done? %08x\n",
+ ep->ep.name, tmp);
+ continue;
}
+ stop_dma(ep->dma);
/* OUT transfers terminate when the data from the
* host is in our memory. Process whatever's done.
@@ -3448,30 +3352,9 @@ static void handle_stat1_irqs(struct net2280 *dev, u32 stat)
scan_dma_completions(ep);
/* disable dma on inactive queues; else maybe restart */
- if (list_empty(&ep->queue)) {
- if (use_dma_chaining)
- stop_dma(ep->dma);
- } else {
+ if (!list_empty(&ep->queue)) {
tmp = readl(&dma->dmactl);
- if (!use_dma_chaining || (tmp & BIT(DMA_ENABLE)) == 0)
- restart_dma(ep);
- else if (ep->is_in && use_dma_chaining) {
- struct net2280_request *req;
- __le32 dmacount;
-
- /* the descriptor at the head of the chain
- * may still have VALID_BIT clear; that's
- * used to trigger changing DMA_FIFO_VALIDATE
- * (affects automagic zlp writes).
- */
- req = list_entry(ep->queue.next,
- struct net2280_request, queue);
- dmacount = req->td->dmacount;
- dmacount &= cpu_to_le32(BIT(VALID_BIT) |
- DMA_BYTE_COUNT_MASK);
- if (dmacount && (dmacount & valid_bit) == 0)
- restart_dma(ep);
- }
+ restart_dma(ep);
}
ep->irqs++;
}
@@ -3581,9 +3464,6 @@ static int net2280_probe(struct pci_dev *pdev, const struct pci_device_id *id)
void __iomem *base = NULL;
int retval, i;
- if (!use_dma)
- use_dma_chaining = 0;
-
/* alloc, and start init */
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev == NULL) {
@@ -3742,8 +3622,7 @@ static int net2280_probe(struct pci_dev *pdev, const struct pci_device_id *id)
ep_info(dev, "irq %d, pci mem %p, chip rev %04x\n",
pdev->irq, base, dev->chiprev);
ep_info(dev, "version: " DRIVER_VERSION "; dma %s %s\n",
- use_dma ? (use_dma_chaining ? "chaining" : "enabled")
- : "disabled",
+ use_dma ? "enabled" : "disabled",
dev->enhanced_mode ? "enhanced mode" : "legacy mode");
retval = device_create_file(&pdev->dev, &dev_attr_registers);
if (retval)
--
2.1.3
--
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