From: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxx: don't introduce CamelCase,
shrink diff]
Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/musb/musb_gadget.c | 33 ++++++++++------
drivers/usb/musb/musb_host.c | 79 +++++++++++++++------------------------
drivers/usb/musb/musbhsdma.c | 57 +++++++++++++++++-----------
3 files changed, 89 insertions(+), 80 deletions(-)
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -165,9 +165,15 @@ static void nuke(struct musb_ep *ep, con
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 @@ static inline int max_ep_writesize(struc
| 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 @@ static void txstate(struct musb *musb, s
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 @@ static void txstate(struct musb *musb, s
#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 @@ static void txstate(struct musb *musb, s
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)
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -593,10 +593,17 @@ musb_rx_reinit(struct musb *musb, struct
csr = musb_readw(ep->regs, MUSB_TXCSR);
if (csr & MUSB_TXCSR_MODE) {
musb_h_tx_flush_fifo(ep);
+ csr = musb_readw(ep->regs, MUSB_TXCSR);
musb_writew(ep->regs, MUSB_TXCSR,
- MUSB_TXCSR_FRCDATATOG);
+ csr | MUSB_TXCSR_FRCDATATOG);
}
- /* clear mode (and everything else) to enable Rx */
+
+ /*
+ * Clear the MODE bit (and everything else) to enable Rx.
+ * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
+ */
+ if (csr & MUSB_TXCSR_DMAMODE)
+ musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
musb_writew(ep->regs, MUSB_TXCSR, 0);
/* scrub all previous state, clearing toggle */
@@ -693,12 +700,17 @@ static void musb_ep_program(struct musb
/* general endpoint setup */
if (epnum) {
- /* ASSERT: TXCSR_DMAENAB was already cleared */
-
/* flush all old state, set default */
musb_h_tx_flush_fifo(hw_ep);
+
+ /*
+ * We must not clear the DMAMODE bit before or in
+ * the same cycle with the DMAENAB bit, so we clear
+ * the latter first...
+ */
csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
- | MUSB_TXCSR_DMAMODE
+ | MUSB_TXCSR_AUTOSET
+ | MUSB_TXCSR_DMAENAB
| MUSB_TXCSR_FRCDATATOG
| MUSB_TXCSR_H_RXSTALL
| MUSB_TXCSR_H_ERROR
@@ -706,16 +718,15 @@ static void musb_ep_program(struct musb
);
csr |= MUSB_TXCSR_MODE;
- if (usb_gettoggle(urb->dev,
- qh->epnum, 1))
+ if (usb_gettoggle(urb->dev, qh->epnum, 1))
csr |= MUSB_TXCSR_H_WR_DATATOGGLE
| MUSB_TXCSR_H_DATATOGGLE;
else
csr |= MUSB_TXCSR_CLRDATATOG;
- /* twice in case of double packet buffering */
musb_writew(epio, MUSB_TXCSR, csr);
/* REVISIT may need to clear FLUSHFIFO ... */
+ csr &= ~MUSB_TXCSR_DMAMODE;
musb_writew(epio, MUSB_TXCSR, csr);
csr = musb_readw(epio, MUSB_TXCSR);
} else {
@@ -759,34 +770,19 @@ static void musb_ep_program(struct musb
#ifdef CONFIG_USB_INVENTRA_DMA
if (dma_channel) {
-
- /* clear previous state */
- csr = musb_readw(epio, MUSB_TXCSR);
- csr &= ~(MUSB_TXCSR_AUTOSET
- | MUSB_TXCSR_DMAMODE
- | MUSB_TXCSR_DMAENAB);
- csr |= MUSB_TXCSR_MODE;
- musb_writew(epio, MUSB_TXCSR,
- csr | MUSB_TXCSR_MODE);
-
qh->segsize = min(len, dma_channel->max_len);
-
if (qh->segsize <= packet_sz)
dma_channel->desired_mode = 0;
else
dma_channel->desired_mode = 1;
-
if (dma_channel->desired_mode == 0) {
- csr &= ~(MUSB_TXCSR_AUTOSET
- | MUSB_TXCSR_DMAMODE);
+ /* Against the programming guide */
csr |= (MUSB_TXCSR_DMAENAB);
- /* against programming guide */
} else
csr |= (MUSB_TXCSR_AUTOSET
| MUSB_TXCSR_DMAENAB
| MUSB_TXCSR_DMAMODE);
-
musb_writew(epio, MUSB_TXCSR, csr);
dma_ok = dma_controller->channel_program(
@@ -803,6 +799,17 @@ static void musb_ep_program(struct musb
else
hw_ep->rx_channel = NULL;
dma_channel = NULL;
+
+ /*
+ * The programming guide says that we must
+ * clear the DMAENAB bit before DMAMODE...
+ */
+ csr = musb_readw(epio, MUSB_TXCSR);
+ csr &= ~(MUSB_TXCSR_DMAENAB
+ | MUSB_TXCSR_AUTOSET);
+ musb_writew(epio, MUSB_TXCSR, csr);
+ csr &= ~MUSB_TXCSR_DMAMODE;
+ musb_writew(epio, MUSB_TXCSR, csr);
}
}
#endif
@@ -810,18 +817,7 @@ static void musb_ep_program(struct musb
/* candidate for DMA */
if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
- /* program endpoint CSRs first, then setup DMA.
- * assume CPPI setup succeeds.
- * defer enabling dma.
- */
- csr = musb_readw(epio, MUSB_TXCSR);
- csr &= ~(MUSB_TXCSR_AUTOSET
- | MUSB_TXCSR_DMAMODE
- | MUSB_TXCSR_DMAENAB);
- csr |= MUSB_TXCSR_MODE;
- musb_writew(epio, MUSB_TXCSR,
- csr | MUSB_TXCSR_MODE);
-
+ /* Defer enabling DMA */
dma_channel->actual_len = 0L;
qh->segsize = len;
@@ -850,20 +846,9 @@ static void musb_ep_program(struct musb
}
if (load_count) {
- /* ASSERT: TXCSR_DMAENAB was already cleared */
-
/* PIO to load FIFO */
qh->segsize = load_count;
musb_write_fifo(hw_ep, load_count, buf);
- csr = musb_readw(epio, MUSB_TXCSR);
- csr &= ~(MUSB_TXCSR_DMAENAB
- | MUSB_TXCSR_DMAMODE
- | MUSB_TXCSR_AUTOSET);
- /* write CSR */
- csr |= MUSB_TXCSR_MODE;
-
- if (epnum)
- musb_writew(epio, MUSB_TXCSR, csr);
}
/* re-enable interrupt */
--- a/drivers/usb/musb/musbhsdma.c
+++ b/drivers/usb/musb/musbhsdma.c
@@ -195,30 +195,32 @@ static int dma_channel_abort(struct dma_
void __iomem *mbase = musb_channel->controller->base;
u8 bchannel = musb_channel->idx;
+ int offset;
u16 csr;
if (channel->status == MUSB_DMA_STATUS_BUSY) {
if (musb_channel->transmit) {
+ offset = MUSB_EP_OFFSET(musb_channel->epnum,
+ MUSB_TXCSR);
- csr = musb_readw(mbase,
- MUSB_EP_OFFSET(musb_channel->epnum,
- MUSB_TXCSR));
- csr &= ~(MUSB_TXCSR_AUTOSET |
- MUSB_TXCSR_DMAENAB |
- MUSB_TXCSR_DMAMODE);
- musb_writew(mbase,
- MUSB_EP_OFFSET(musb_channel->epnum, MUSB_TXCSR),
- csr);
+ /*
+ * The programming guide says that we must clear
+ * the DMAENAB bit before the DMAMODE bit...
+ */
+ csr = musb_readw(mbase, offset);
+ csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
+ musb_writew(mbase, offset, csr);
+ csr &= ~MUSB_TXCSR_DMAMODE;
+ musb_writew(mbase, offset, csr);
} else {
- csr = musb_readw(mbase,
- MUSB_EP_OFFSET(musb_channel->epnum,
- MUSB_RXCSR));
+ offset = MUSB_EP_OFFSET(musb_channel->epnum,
+ MUSB_RXCSR);
+
+ csr = musb_readw(mbase, offset);
csr &= ~(MUSB_RXCSR_AUTOCLEAR |
MUSB_RXCSR_DMAENAB |
MUSB_RXCSR_DMAMODE);
- musb_writew(mbase,
- MUSB_EP_OFFSET(musb_channel->epnum, MUSB_RXCSR),
- csr);
+ musb_writew(mbase, offset, csr);
}
musb_writew(mbase,
@@ -296,14 +298,25 @@ static irqreturn_t dma_controller_irq(in
&& ((channel->desired_mode == 0)
|| (channel->actual_len &
(musb_channel->max_packet_sz - 1)))
- ) {
+ ) {
+ u8 epnum = musb_channel->epnum;
+ int offset = MUSB_EP_OFFSET(epnum,
+ MUSB_TXCSR);
+ u16 txcsr;
+
+ /*
+ * The programming guide says that we
+ * must clear DMAENAB before DMAMODE.
+ */
+ musb_ep_select(mbase, epnum);
+ txcsr = musb_readw(mbase, offset);
+ txcsr &= ~(MUSB_TXCSR_DMAENAB
+ | MUSB_TXCSR_AUTOSET);
+ musb_writew(mbase, offset, txcsr);
/* Send out the packet */
- musb_ep_select(mbase,
- musb_channel->epnum);
- musb_writew(mbase, MUSB_EP_OFFSET(
- musb_channel->epnum,
- MUSB_TXCSR),
- MUSB_TXCSR_TXPKTRDY);
+ txcsr &= ~MUSB_TXCSR_DMAMODE;
+ txcsr |= MUSB_TXCSR_TXPKTRDY;
+ musb_writew(mbase, offset, txcsr);
}
musb_dma_completion(musb, musb_channel->epnum,
musb_channel->transmit);
--
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