diff options
Diffstat (limited to 'drivers/usb/musb/musb_cppi41.c')
| -rw-r--r-- | drivers/usb/musb/musb_cppi41.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index 47ae6455d07..3ee133f675a 100644 --- a/drivers/usb/musb/musb_cppi41.c +++ b/drivers/usb/musb/musb_cppi41.c @@ -39,6 +39,7 @@ struct cppi41_dma_channel { u32 transferred; u32 packet_sz; struct list_head tx_check; + int tx_zlp; }; #define MUSB_DMA_NUM_CHANNELS 15 @@ -122,6 +123,8 @@ static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel) { struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep; struct musb *musb = hw_ep->musb; + void __iomem *epio = hw_ep->regs; + u16 csr; if (!cppi41_channel->prog_len || (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) { @@ -131,15 +134,24 @@ static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel) cppi41_channel->transferred; cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE; cppi41_channel->channel.rx_packet_done = true; + + /* + * transmit ZLP using PIO mode for transfers which size is + * multiple of EP packet size. + */ + if (cppi41_channel->tx_zlp && (cppi41_channel->transferred % + cppi41_channel->packet_sz) == 0) { + musb_ep_select(musb->mregs, hw_ep->epnum); + csr = MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY; + musb_writew(epio, MUSB_TXCSR, csr); + } musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx); } else { /* next iteration, reload */ struct dma_chan *dc = cppi41_channel->dc; struct dma_async_tx_descriptor *dma_desc; enum dma_transfer_direction direction; - u16 csr; u32 remain_bytes; - void __iomem *epio = cppi41_channel->hw_ep->regs; cppi41_channel->buf_addr += cppi41_channel->packet_sz; @@ -363,6 +375,7 @@ static bool cppi41_configure_channel(struct dma_channel *channel, cppi41_channel->total_len = len; cppi41_channel->transferred = 0; cppi41_channel->packet_sz = packet_sz; + cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0; /* * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more |