From 9267edaf8cd7b0ef2cd7785c677fe792c077b6ab Mon Sep 17 00:00:00 2001
From: Bin Liu <b-liu@ti.com>
Date: Tue, 12 Aug 2014 14:18:43 -0500
Subject: [PATCH] usb: musb: cppi41: fix not transmitting zero length packet
issue
CPPI TX does not transmit ZLP for TX transfers which
- transfer size is multiple of EP packet size,
- and URB_ZERO_PACKET is set in urb->transfer_flags.
The fix is transmitting the ZLP using PIO mode after the CPPI TX is
done.
Validated using the following usbtest write case in MUSB host mode.
# testusb -t1 -c1
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/musb/musb_cppi41.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 47ae6455d0733..3ee133f675abe 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
--
GitLab