Remove the pointless 'do () while (0)' loop from musb_g_tx() -- it
makes this function symmetric to musb_g_rx()...
Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
---
Greg, please replace the usb/usb-musb_gadget-remove-pointless-loop.patch
in your series with this, fixed up one.
Changes since the previous take:
- eliminated the erratic optimization at end of musb_g_tx()...
drivers/usb/musb/musb_gadget.c | 170 +++++++++++++++++++----------------------
1 files changed, 80 insertions(+), 90 deletions(-)
Index: linux-2.6/drivers/usb/musb/musb_gadget.c
===================================================================
--- linux-2.6.orig/drivers/usb/musb/musb_gadget.c
+++ linux-2.6/drivers/usb/musb/musb_gadget.c
@@ -429,112 +429,102 @@ void musb_g_tx(struct musb *musb, u8 epn
DBG(4, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr);
dma = is_dma_capable() ? musb_ep->dma : NULL;
- do {
- /* REVISIT for high bandwidth, MUSB_TXCSR_P_INCOMPTX
- * probably rates reporting as a host error
+
+ /*
+ * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
+ * probably rates reporting as a host error.
+ */
+ if (csr & MUSB_TXCSR_P_SENTSTALL) {
+ csr |= MUSB_TXCSR_P_WZC_BITS;
+ csr &= ~MUSB_TXCSR_P_SENTSTALL;
+ musb_writew(epio, MUSB_TXCSR, csr);
+ return;
+ }
+
+ if (csr & MUSB_TXCSR_P_UNDERRUN) {
+ /* We NAKed, no big deal... little reason to care. */
+ csr |= MUSB_TXCSR_P_WZC_BITS;
+ csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
+ musb_writew(epio, MUSB_TXCSR, csr);
+ DBG(20, "underrun on ep%d, req %p\n", epnum, request);
+ }
+
+ if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+ /*
+ * SHOULD NOT HAPPEN... has with CPPI though, after
+ * changing SENDSTALL (and other cases); harmless?
*/
- if (csr & MUSB_TXCSR_P_SENTSTALL) {
- csr |= MUSB_TXCSR_P_WZC_BITS;
- csr &= ~MUSB_TXCSR_P_SENTSTALL;
- musb_writew(epio, MUSB_TXCSR, csr);
- break;
- }
+ DBG(5, "%s dma still busy?\n", musb_ep->end_point.name);
+ return;
+ }
- if (csr & MUSB_TXCSR_P_UNDERRUN) {
- /* we NAKed, no big deal ... little reason to care */
+ if (request) {
+ u8 is_dma = 0;
+
+ if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
+ is_dma = 1;
csr |= MUSB_TXCSR_P_WZC_BITS;
- csr &= ~(MUSB_TXCSR_P_UNDERRUN
- | MUSB_TXCSR_TXPKTRDY);
+ csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
+ MUSB_TXCSR_TXPKTRDY);
musb_writew(epio, MUSB_TXCSR, csr);
- DBG(20, "underrun on ep%d, req %p\n", epnum, request);
+ /* Ensure writebuffer is empty. */
+ csr = musb_readw(epio, MUSB_TXCSR);
+ request->actual += musb_ep->dma->actual_len;
+ DBG(4, "TXCSR%d %04x, DMA off, len %zu, req %p\n",
+ epnum, csr, musb_ep->dma->actual_len, request);
}
- if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
- /* SHOULD NOT HAPPEN ... has with cppi though, after
- * changing SENDSTALL (and other cases); harmless?
+ if (is_dma || request->actual == request->length) {
+ /*
+ * First, maybe a terminating short packet. Some DMA
+ * engines might handle this by themselves.
*/
- DBG(5, "%s dma still busy?\n", musb_ep->end_point.name);
- break;
- }
-
- if (request) {
- u8 is_dma = 0;
+ if ((request->zero && request->length
+ && request->length % musb_ep->packet_sz == 0)
+#ifdef CONFIG_USB_INVENTRA_DMA
+ || (is_dma && (!dma->desired_mode ||
+ (request->actual &
+ (musb_ep->packet_sz - 1))))
+#endif
+ ) {
+ /*
+ * On DMA completion, FIFO may not be
+ * available yet...
+ */
+ if (csr & MUSB_TXCSR_TXPKTRDY)
+ return;
- if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
- is_dma = 1;
- csr |= MUSB_TXCSR_P_WZC_BITS;
- csr &= ~(MUSB_TXCSR_DMAENAB
- | MUSB_TXCSR_P_UNDERRUN
+ DBG(4, "sending zero pkt\n");
+ musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
| MUSB_TXCSR_TXPKTRDY);
- musb_writew(epio, MUSB_TXCSR, csr);
- /* ensure writebuffer is empty */
- csr = musb_readw(epio, MUSB_TXCSR);
- request->actual += musb_ep->dma->actual_len;
- DBG(4, "TXCSR%d %04x, dma off, "
- "len %zu, req %p\n",
- epnum, csr,
- musb_ep->dma->actual_len,
- request);
+ request->zero = 0;
}
- if (is_dma || request->actual == request->length) {
+ /* ... or if not, then complete it. */
+ musb_g_giveback(musb_ep, request, 0);
- /* First, maybe a terminating short packet.
- * Some DMA engines might handle this by
- * themselves.
- */
- if ((request->zero
- && request->length
- && (request->length
- % musb_ep->packet_sz)
- == 0)
-#ifdef CONFIG_USB_INVENTRA_DMA
- || (is_dma &&
- ((!dma->desired_mode) ||
- (request->actual &
- (musb_ep->packet_sz - 1))))
-#endif
- ) {
- /* on dma completion, fifo may not
- * be available yet ...
- */
- if (csr & MUSB_TXCSR_TXPKTRDY)
- break;
-
- DBG(4, "sending zero pkt\n");
- musb_writew(epio, MUSB_TXCSR,
- MUSB_TXCSR_MODE
- | MUSB_TXCSR_TXPKTRDY);
- request->zero = 0;
- }
-
- /* ... or if not, then complete it */
- musb_g_giveback(musb_ep, request, 0);
+ /*
+ * Kickstart next transfer if appropriate;
+ * the packet that just completed might not
+ * be transmitted for hours or days.
+ * REVISIT for double buffering...
+ * FIXME revisit for stalls too...
+ */
+ musb_ep_select(mbase, epnum);
+ csr = musb_readw(epio, MUSB_TXCSR);
+ if (csr & MUSB_TXCSR_FIFONOTEMPTY)
+ return;
- /* kickstart next transfer if appropriate;
- * the packet that just completed might not
- * be transmitted for hours or days.
- * REVISIT for double buffering...
- * FIXME revisit for stalls too...
- */
- musb_ep_select(mbase, epnum);
- csr = musb_readw(epio, MUSB_TXCSR);
- if (csr & MUSB_TXCSR_FIFONOTEMPTY)
- break;
- request = musb_ep->desc
- ? next_request(musb_ep)
- : NULL;
- if (!request) {
- DBG(4, "%s idle now\n",
- musb_ep->end_point.name);
- break;
- }
+ request = musb_ep->desc ? next_request(musb_ep) : NULL;
+ if (!request) {
+ DBG(4, "%s idle now\n",
+ musb_ep->end_point.name);
+ return;
}
-
- txstate(musb, to_musb_request(request));
}
- } while (0);
+ txstate(musb, to_musb_request(request));
+ }
}
/* ------------------------------------------------------------ */
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