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authorBrian Cully <bjc@kublai.com>2019-10-08 09:51:19 -0400
committerBrian Cully <bjc@kublai.com>2019-10-08 09:51:19 -0400
commitd1dd984b7eea72618a22a76b2f67cf6f79804cd5 (patch)
tree24f821181f60207159606b68173ed8b1d378e7ae /src/pipe.rs
parent27996171012333685416a73250d89232fce7a73e (diff)
downloadatsamd-usb-host-d1dd984b7eea72618a22a76b2f67cf6f79804cd5.tar.gz
atsamd-usb-host-d1dd984b7eea72618a22a76b2f67cf6f79804cd5.zip
Cache buffer length on entry to `in_transfer` and `out_transfer`.
Use `ptr.offset()` in `in_transfer`, rather than hand calculations.
Diffstat (limited to 'src/pipe.rs')
-rw-r--r--src/pipe.rs65
1 files changed, 31 insertions, 34 deletions
diff --git a/src/pipe.rs b/src/pipe.rs
index 7db5b6c..814ce63 100644
--- a/src/pipe.rs
+++ b/src/pipe.rs
@@ -246,55 +246,51 @@ impl Pipe<'_, '_> {
millis: &dyn Fn() -> usize,
) -> Result<usize, PipeErr> {
let packet_size = ep.max_packet_size() as isize;
+ let buflen = buf.len() as isize;
- trace!("p{}: Should IN for {}b.", self.num, buf.len());
+ trace!("p{}: Should IN for {}b.", self.num, buflen);
self.desc.bank0.pcksize.modify(|_, w| {
- unsafe { w.byte_count().bits(buf.len() as u16) };
+ unsafe { w.byte_count().bits(buflen as u16) };
unsafe { w.multi_packet_size().bits(0) }
});
// Read until we get a short packet (indicating that there's
// nothing left for us in this transaction) or the buffer is
// full.
- //
- // TODO: It is sometimes valid to get a short packet when
- // variable length data is desired by the driver. cf §5.3.2 of
- // USB 2.0.
- let mut bytes_received = 0;
- while bytes_received < buf.len() {
+ let ptr: *mut u8 = buf.as_mut_ptr();
+ let mut bytes_received = 0isize;
+ loop {
// Move the buffer pointer forward as we get data.
- self.desc.bank0.addr.write(|w| unsafe {
- w.addr()
- .bits(buf.as_mut_ptr() as u32 + bytes_received as u32)
- });
- self.regs.statusclr.write(|w| w.bk0rdy().set_bit());
- trace!("--- !!! regs-pre-dispatch !!! ---");
- self.log_regs();
-
+ self.desc
+ .bank0
+ .addr
+ .write(|w| unsafe { w.addr().bits(ptr.offset(bytes_received) as u32) });
self.dispatch_retries(ep, PToken::In, nak_limit, millis)?;
- let recvd = self.desc.bank0.pcksize.read().byte_count().bits() as usize;
+ let recvd = self.desc.bank0.pcksize.read().byte_count().bits() as isize;
bytes_received += recvd;
- trace!("!! read {} of {}", bytes_received, buf.len());
- if recvd < packet_size {
- break;
- }
+
+ trace!("p{}: read {} of {}", self.num, bytes_received, buflen);
// Don't allow writing past the buffer.
- assert!(bytes_received <= buf.len());
+ assert!(bytes_received <= buflen);
+
+ if bytes_received == buflen {
+ break;
+ } else if recvd < packet_size {
+ warn!("p{}: short packet {}/{}.", self.num, recvd, packet_size);
+ break;
+ }
}
self.regs.statusset.write(|w| w.pfreeze().set_bit());
- if bytes_received < buf.len() {
+ if bytes_received < buflen {
+ // TODO: It is sometimes valid to get a short packet when
+ // variable length data is desired by the driver. cf
+ // §5.3.2 of USB 2.0.
self.log_regs();
- // TODO: honestly, this is probably a panic condition,
- // since whatever's in DataBuf.ptr is totally
- // invalid. Alternately, this function should be declared
- // `unsafe`. OR! Make the function take a mutable slice of
- // u8, and leave it up to the caller to figure out how to
- // deal with short packets.
Err(PipeErr::ShortPacket)
} else {
- Ok(bytes_received)
+ Ok(bytes_received as usize)
}
}
@@ -305,14 +301,15 @@ impl Pipe<'_, '_> {
nak_limit: usize,
millis: &dyn Fn() -> usize,
) -> Result<usize, PipeErr> {
- trace!("p{}: Should OUT for {}b.", self.num, buf.len());
+ let buflen = buf.len();
+ trace!("p{}: Should OUT for {}b.", self.num, buflen);
self.desc.bank0.pcksize.modify(|_, w| {
- unsafe { w.byte_count().bits(buf.len() as u16) };
+ unsafe { w.byte_count().bits(buflen as u16) };
unsafe { w.multi_packet_size().bits(0) }
});
let mut bytes_sent = 0;
- while bytes_sent < buf.len() {
+ while bytes_sent < buflen {
self.desc
.bank0
.addr
@@ -321,7 +318,7 @@ impl Pipe<'_, '_> {
let sent = self.desc.bank0.pcksize.read().byte_count().bits() as usize;
bytes_sent += sent;
- trace!("!! wrote {} of {}", bytes_sent, buf.len());
+ trace!("!! wrote {} of {}", bytes_sent, buflen);
}
Ok(bytes_sent)