MUSB RTL version 1.8 onward (OMAP3630, AM/DM37x, OMAP4) DMA requires the buffers to be aligned on a four byte boundary. This affects USB CDC/RNDIS class application where buffers are always unaligned.
Use system DMA for unaligned buffers as a workaround of this issue. Current patch set supports device side CDC/RNDIS. Host side would require change in Tx programming path for mode-0 operation when transfer length is more than packet size. Signed-off-by: Ajay Kumar Gupta <[email protected]> --- Patch created against linus'tree + all musb patches in Greg's queue Changes from v1: - Added wrapper function to make it compilable for BlackFins drivers/usb/musb/Kconfig | 6 +++ drivers/usb/musb/musbhsdma.c | 103 ++++++++++++++++++++++++++++++++--------- 2 files changed, 86 insertions(+), 23 deletions(-) diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig index be5bea6..f518339 100644 --- a/drivers/usb/musb/Kconfig +++ b/drivers/usb/musb/Kconfig @@ -166,6 +166,12 @@ config MUSB_USE_SYSTEM_DMA_WORKAROUND DMA channels are simultaneously enabled. To work around this issue, you can choose to use System DMA for RX channels. + Also on Mentor DMA in MUSB RTL version 1.8 (OMAP3630, AM/DM37x) + requires buffers to be aligned on a four byte boundary. This affects + USB CDC/RNDIS class application where buffers are always unaligned. + To work around this issue, you can choose to use System DMA for + unaligned buffers. + config USB_TI_CPPI_DMA bool depends on USB_MUSB_HDRC && !MUSB_PIO_ONLY diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c index d2dab57..d29e487 100644 --- a/drivers/usb/musb/musbhsdma.c +++ b/drivers/usb/musb/musbhsdma.c @@ -52,8 +52,7 @@ static void musb_sdma_channel_program(struct musb *musb, struct musb_dma_channel *musb_channel, dma_addr_t dma_addr, u32 len) { - /* System DMA */ - /* RX: set src = FIFO */ + /* set transfer parameters */ omap_set_dma_transfer_params(musb_channel->sysdma_channel, OMAP_DMA_DATA_TYPE_S8, len ? len : 1, 1, /* One frame */ @@ -61,20 +60,39 @@ static void musb_sdma_channel_program(struct musb *musb, OMAP24XX_DMA_NO_DEVICE, 0); /* Src Sync */ - omap_set_dma_src_params(musb_channel->sysdma_channel, 0, - OMAP_DMA_AMODE_CONSTANT, - MUSB_FIFO_ADDRESS(musb->ctrl_phys_base, - musb_channel->epnum), - 0, 0); - - omap_set_dma_dest_params(musb_channel->sysdma_channel, 0, - OMAP_DMA_AMODE_POST_INC, dma_addr, - 0, 0); - - omap_set_dma_dest_data_pack(musb_channel->sysdma_channel, 1); - omap_set_dma_dest_burst_mode(musb_channel->sysdma_channel, - OMAP_DMA_DATA_BURST_16); - + if (!musb_channel->transmit) { + /* RX: set src = FIFO */ + omap_set_dma_src_params(musb_channel->sysdma_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + MUSB_FIFO_ADDRESS(musb->ctrl_phys_base, + musb_channel->epnum), + 0, 0); + + omap_set_dma_dest_params(musb_channel->sysdma_channel, 0, + OMAP_DMA_AMODE_POST_INC, dma_addr, + 0, 0); + + omap_set_dma_dest_data_pack(musb_channel->sysdma_channel, 1); + omap_set_dma_dest_burst_mode(musb_channel->sysdma_channel, + OMAP_DMA_DATA_BURST_16); + + } else if (musb_channel->transmit) { + /* TX: set dst = FIFO */ + omap_set_dma_src_params(musb_channel->sysdma_channel, 0, + OMAP_DMA_AMODE_POST_INC, dma_addr, + 0, 0); + + omap_set_dma_dest_params(musb_channel->sysdma_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + MUSB_FIFO_ADDRESS(musb->ctrl_phys_base, + musb_channel->epnum), + 0, 0); + + omap_set_dma_dest_data_pack(musb_channel->sysdma_channel, 0); + omap_set_dma_dest_burst_mode(musb_channel->sysdma_channel, + OMAP_DMA_DATA_BURST_DIS); + } + /* start the system dma */ omap_start_dma(musb_channel->sysdma_channel); } static void musb_sysdma_completion(int lch, u16 ch_status, void *data) @@ -88,12 +106,18 @@ static void musb_sysdma_completion(int lch, u16 ch_status, void *data) (struct musb_dma_channel *) data; struct musb_dma_controller *controller = musb_channel->controller; struct musb *musb = controller->private_data; + void __iomem *mbase = controller->base; + channel = &musb_channel->channel; DBG(2, "lch = 0x%d, ch_status = 0x%x\n", lch, ch_status); spin_lock_irqsave(&musb->lock, flags); - addr = (u32) omap_get_dma_dst_pos(musb_channel->sysdma_channel); + if (musb_channel->transmit) + addr = (u32) omap_get_dma_src_pos(musb_channel->sysdma_channel); + else + addr = (u32) omap_get_dma_dst_pos(musb_channel->sysdma_channel); + if (musb_channel->len == 0) channel->actual_len = 0; else @@ -106,6 +130,26 @@ static void musb_sysdma_completion(int lch, u16 ch_status, void *data) "=> reconfig 0 " : " => complete"); channel->status = MUSB_DMA_STATUS_FREE; + + /* completed */ + if ((musb_channel->transmit) && (channel->desired_mode == 0) + && (channel->actual_len == musb_channel->max_packet_sz)) { + + 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_TXPKTRDY; + musb_writew(mbase, offset, txcsr); + } + musb_dma_completion(musb, musb_channel->epnum, musb_channel->transmit); spin_unlock_irqrestore(&musb->lock, flags); @@ -194,8 +238,15 @@ static struct dma_channel *dma_channel_allocate(struct dma_controller *c, * issue when TX and RX DMA channels are simultaneously * enabled. To work around this issue, use system DMA * for all RX channels. + * Also on MUSB RTL version 1.8 onward (OMAP3630, OMAP4 + * and AM/DM37x) DMA requires buffers to be aligned on + * a four byte boundary. This affects USB CDC/RNDIS + * class application where buffers are always unaligned. + * Using system DMA for unaligned buffers as a + * workaround for this issue. */ - if (((musb->hwvers == MUSB_HWVERS_1400) && !transmit) + if ((((musb->hwvers == MUSB_HWVERS_1400) && !transmit) + || (musb->hwvers >= MUSB_HWVERS_1800)) && use_sdma_workaround()) { int ret; ret = musb_sdma_channel_request( @@ -248,11 +299,18 @@ static void configure_channel(struct dma_channel *channel, struct musb *musb = controller->private_data; void __iomem *mbase = controller->base; u8 bchannel = musb_channel->idx; + u8 buffer_is_aligned = (dma_addr & 0x3) ? 0 : 1; + u8 use_sdma = (musb_channel->sysdma_channel == -1) ? 0 : 1; u16 csr = 0; DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n", channel, packet_sz, dma_addr, len, mode); - if (musb_channel->sysdma_channel != -1) { + + if (buffer_is_aligned && (packet_sz >= 512) && + (musb->hwvers >= MUSB_HWVERS_1800)) + use_sdma = 0; + + if (use_sdma) { musb_sdma_channel_program(musb, musb_channel, dma_addr, len); } else { /* Mentor DMA */ @@ -328,6 +386,9 @@ static int dma_channel_abort(struct dma_channel *channel) u16 csr; if (channel->status == MUSB_DMA_STATUS_BUSY) { + if (musb_channel->sysdma_channel != -1) + musb_sdma_channel_abort(musb_channel->sysdma_channel); + if (musb_channel->transmit) { offset = MUSB_EP_OFFSET(musb_channel->epnum, MUSB_TXCSR); @@ -342,10 +403,6 @@ static int dma_channel_abort(struct dma_channel *channel) csr &= ~MUSB_TXCSR_DMAMODE; musb_writew(mbase, offset, csr); } else { - if (musb_channel->sysdma_channel != -1) - musb_sdma_channel_abort( - musb_channel->sysdma_channel); - offset = MUSB_EP_OFFSET(musb_channel->epnum, MUSB_RXCSR); -- 1.6.2.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
