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usb: musb: introduce dma_channel.rx_packet_done 

The musb/cppi41 glue layer is capable of handling transactions that span
over more than one USB packet by reloading the DMA descriptors
partially. An urb is considered completed when either its transfer
buffer has been filled entirely (actual_length ==
transfer_buffer_length) or if a packet in the stream has less bytes than
the endpoint's wMaxPacketSize.

Once one of the above conditions is met, musb_dma_completion() is called
from cppi41_trans_done(). However, the final decision whether or not to
return the urb to its owner is made by the core and its determination of
the variable 'done' in musb_host_rx(). This code has currently no way of
knowing what the size of the last packet was, and whether or not to
give back the urb due to a short read.

Fix this by introducing a new boolean flag in 'struct dma_channel', and
set it from musb_cppi41.c. If set, it will make the core do what the
DMA layer decided and complete the urb.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Daniel Mack 2014-05-26 14:52:38 +02:00 committed by Felipe Balbi
parent 2ccc6d30a0
commit ff3fcac949
3 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/usb/musb/musb_cppi41.c
View File

@ -139,6 +139,7 @@ static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
cppi41_channel->channel.actual_len =
cppi41_channel->transferred;
cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
cppi41_channel->channel.rx_packet_done = true;
musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
} else {
/* next iteration, reload */
@ -450,6 +451,7 @@ static bool cppi41_configure_channel(struct dma_channel *channel,
dma_desc->callback = cppi41_dma_callback;
dma_desc->callback_param = channel;
cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
cppi41_channel->channel.rx_packet_done = false;
save_rx_toggle(cppi41_channel);
dma_async_issue_pending(dc);

1
drivers/usb/musb/musb_dma.h
View File

@ -129,6 +129,7 @@ struct dma_channel {
size_t actual_len;
enum dma_channel_status status;
bool desired_mode;
bool rx_packet_done;
};
/*

3
drivers/usb/musb/musb_host.c
View File

@ -1737,7 +1737,8 @@ void musb_host_rx(struct musb *musb, u8 epnum)
/* done if urb buffer is full or short packet is recd */
done = (urb->actual_length + xfer_len >=
urb->transfer_buffer_length
|| dma->actual_len < qh->maxpacket);
|| dma->actual_len < qh->maxpacket
|| dma->rx_packet_done);
}
/* send IN token for next packet, without AUTOREQ */