x86: poll waiting for I/OAT DMA channel status
authorDimitri Sivanich <sivanich@sgi.com>
Fri, 6 May 2011 15:33:44 +0000 (10:33 -0500)
committerDan Williams <dan.j.williams@intel.com>
Fri, 27 May 2011 00:11:24 +0000 (17:11 -0700)
commit19d78a61be6dd707dcec298c486303d4ba2c840a
tree57c0bc50540ec0f49b7b972f14cee51bc4f22e60
parent5dbd05d46fb7d849570c8fa09d48591aa7ce1766
x86: poll waiting for I/OAT DMA channel status

For certain system configurations a 5 usec udelay before checking I/OAT DMA
channel status is sometimes not sufficient, resulting in a false failure
status and unnecessary freeing of channel resources.  Conversely, for many
configurations 5 usec is longer than necessary.

Loop for up to 20 usec waiting for successful status before failing.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/dma/ioat/dma_v2.c