A couple of fields in a data structure, which is used by the driver only,
were not initialized properly during the driver's setup.
The primary issue with this bug was that channel->wr_buf_size remained zero,
so calls to dma_sync_single_for_cpu() took place with zero size, and
consequently did nothing.
This had a rather minimal practical impact, because
(a) these calls are NOPs on Intel/AMD platforms, as well as other platforms
with coherent cache, and
(b) it's extremely rare that any cache line would survive between two reads
from a given DMA buffer
Hence no significant practical difference is expected with this patch.
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The API allows the application to flush a host-to-FPGA stream by calling
write() with the data count set to zero. Before this patch, copy_from_user()
was called with a non-zero byte count, which possibly made it attempt to read
from unmapped user memory. Such attempts caused the driver to return -EFAULT
instead of 0, even though the desired operation went through fine.
This patch ensures the driver returns 0 on a successful flush.
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver has been functional and stable throughout the year it has spent
in the staging area. It has been patched for minor bugs, coding style issues
and improvements during this period.
This is the second submission of this move-out, after making several style
improvements, as suggested by Dan Carpenter.
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Eli Billauer