USB: musb: sanitize clearing TXCSR DMA bits (take 2)
The MUSB code clears TXCSR_DMAMODE incorrectly in several
places, either asserting that TXCSR_DMAENAB is clear (when
sometimes it isn't) or clearing both bits together. Recent
versions of the programmer's guide require DMAENAB to be
cleared first, although some older ones didn't.
Fix this and while at it:
- In musb_gadget::txstate(), stop clearing the AUTOSET
and DMAMODE bits for the CPPI case since they never
get set anyway (the former bit is reserved on DaVinci);
but do clear the DMAENAB bit on the DMA error path.
- In musb_host::musb_ep_program(), remove the duplicate
DMA controller specific code code clearing the TXCSR
previous state, add the code to clear TXCSR DMA bits
on the Inventra DMA error path, to replace such code
(executed late) on the PIO path.
- In musbhsdma::dma_channel_abort()/dma_controller_irq(),
add/use the 'offset' variable to avoid MUSB_EP_OFFSET()
invocations on every RXCSR/TXCSR access.
[dbrownell@users.sourceforge.net: don't introduce CamelCase,
shrink diff]
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index c7ebd08..f79440c 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -165,9 +165,15 @@
if (is_dma_capable() && ep->dma) {
struct dma_controller *c = ep->musb->dma_controller;
int value;
+
if (ep->is_in) {
+ /*
+ * The programming guide says that we must not clear
+ * the DMAMODE bit before DMAENAB, so we only
+ * clear it in the second write...
+ */
musb_writew(epio, MUSB_TXCSR,
- 0 | MUSB_TXCSR_FLUSHFIFO);
+ MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
musb_writew(epio, MUSB_TXCSR,
0 | MUSB_TXCSR_FLUSHFIFO);
} else {
@@ -230,7 +236,7 @@
| IN token(s) are recd from Host.
| -> DMA interrupt on completion
| calls TxAvail.
- | -> stop DMA, ~DmaEenab,
+ | -> stop DMA, ~DMAENAB,
| -> set TxPktRdy for last short pkt or zlp
| -> Complete Request
| -> Continue next request (call txstate)
@@ -315,9 +321,17 @@
request->dma, request_size);
if (use_dma) {
if (musb_ep->dma->desired_mode == 0) {
- /* ASSERT: DMAENAB is clear */
- csr &= ~(MUSB_TXCSR_AUTOSET |
- MUSB_TXCSR_DMAMODE);
+ /*
+ * We must not clear the DMAMODE bit
+ * before the DMAENAB bit -- and the
+ * latter doesn't always get cleared
+ * before we get here...
+ */
+ csr &= ~(MUSB_TXCSR_AUTOSET
+ | MUSB_TXCSR_DMAENAB);
+ musb_writew(epio, MUSB_TXCSR, csr
+ | MUSB_TXCSR_P_WZC_BITS);
+ csr &= ~MUSB_TXCSR_DMAMODE;
csr |= (MUSB_TXCSR_DMAENAB |
MUSB_TXCSR_MODE);
/* against programming guide */
@@ -334,10 +348,7 @@
#elif defined(CONFIG_USB_TI_CPPI_DMA)
/* program endpoint CSR first, then setup DMA */
- csr &= ~(MUSB_TXCSR_AUTOSET
- | MUSB_TXCSR_DMAMODE
- | MUSB_TXCSR_P_UNDERRUN
- | MUSB_TXCSR_TXPKTRDY);
+ csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_DMAENAB;
musb_writew(epio, MUSB_TXCSR,
(MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
@@ -364,8 +375,8 @@
if (!use_dma) {
c->channel_release(musb_ep->dma);
musb_ep->dma = NULL;
- /* ASSERT: DMAENAB clear */
- csr &= ~(MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
+ csr &= ~MUSB_TXCSR_DMAENAB;
+ musb_writew(epio, MUSB_TXCSR, csr);
/* invariant: prequest->buf is non-null */
}
#elif defined(CONFIG_USB_TUSB_OMAP_DMA)