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char: xillybus: Fix internal data structure initialization 

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>
This commit is contained in:
Eli Billauer 2016-02-24 10:40:51 +02:00 committed by Greg Kroah-Hartman
parent a75fa12823
commit ba327173ef
1 changed files with 3 additions and 1 deletions
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4
drivers/char/xillybus/xillybus_core.c
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@ -509,7 +509,7 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
channel->log2_element_size = ((format > 2) ?
2 : format);
bytebufsize = channel->rd_buf_size = bufsize *
bytebufsize = bufsize *
(1 << channel->log2_element_size);
buffers = devm_kcalloc(dev, bufnum,
@ -523,6 +523,7 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
if (!is_writebuf) {
channel->num_rd_buffers = bufnum;
channel->rd_buf_size = bytebufsize;
channel->rd_allow_partial = allowpartial;
channel->rd_synchronous = synchronous;
channel->rd_exclusive_open = exclusive_open;
@ -533,6 +534,7 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
bufnum, bytebufsize);
} else if (channelnum > 0) {
channel->num_wr_buffers = bufnum;
channel->wr_buf_size = bytebufsize;
channel->seekable = seekable;
channel->wr_supports_nonempty = supports_nonempty;