From ba327173ef48c12cf6f326441c74f373fa3be220 Mon Sep 17 00:00:00 2001 From: Eli Billauer Date: Wed, 24 Feb 2016 10:40:51 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/char/xillybus/xillybus_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/char/xillybus/xillybus_core.c b/drivers/char/xillybus/xillybus_core.c index 77d6c127e691..dcd19f3f182e 100644 --- a/drivers/char/xillybus/xillybus_core.c +++ b/drivers/char/xillybus/xillybus_core.c @@ -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;