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| author | Frank Li <Frank.Li@nxp.com> | 2023-05-18 16:49:45 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-29 15:52:37 +0100 |
| commit | 2a1c4639d6d6bcee27f74e38f83ffb43579c4733 (patch) | |
| tree | fa5a909c1d73485f3367a6a5f96e87d96df38e67 /drivers/usb/cdns3/cdns3-imx.c | |
| parent | bfb46b424652a3396b92ca3c96c169ade9b45b8d (diff) | |
| download | linux-2a1c4639d6d6bcee27f74e38f83ffb43579c4733.tar.gz linux-2a1c4639d6d6bcee27f74e38f83ffb43579c4733.tar.bz2 linux-2a1c4639d6d6bcee27f74e38f83ffb43579c4733.zip | |
usb: cdns3: improve handling of unaligned address case
When the address of a request was not aligned with an 8-byte boundary, the
USB DMA was unable to process it, necessitating the use of an internal
bounce buffer.
In these cases, the request->buf had to be copied to/from this bounce
buffer. However, if this unaligned address scenario arises, it is
unnecessary to perform heavy cache maintenance operations like
usb_gadget_map(unmap)_request_by_dev() on the request->buf, as the DMA
does not utilize it at all. it can be skipped at this case.
iperf3 tests on the rndis case:
Transmit speed (TX): Improved from 299Mbps to 440Mbps
Receive speed (RX): Improved from 290Mbps to 500Mbps
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20230518204947.3770236-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/cdns3/cdns3-imx.c')
0 files changed, 0 insertions, 0 deletions