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Commit ba327173 authored by Eli Billauer's avatar Eli Billauer Committed by Greg Kroah-Hartman
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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: default avatarEli Billauer <eli.billauer@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a75fa128

drivers/char/xillybus/xillybus_core.c

+3 −1
Original line number Diff line number Diff line
@@ -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;