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author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2011-07-20 00:56:21 (GMT) |
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committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2011-08-04 11:59:07 (GMT) |
commit | 945a51517cc0bd9e461f2018624dfc1faef9ddee (patch) | |
tree | 5782ffe27f3fb8f5b4cbc19ffe7b74bff36c6a05 /usr | |
parent | d3e614577198757d5854caa912e88f2d4296479b (diff) | |
download | linux-fsl-qoriq-945a51517cc0bd9e461f2018624dfc1faef9ddee.tar.xz |
intel drivers: repair missing flush operations
after review of all intel drivers, found several instances where
drivers had the incorrect pattern of:
memory mapped write();
delay();
which should always be:
memory mapped write();
write flush(); /* aka memory mapped read */
delay();
explanation:
The reason for including the flush is that writes can be held
(posted) in PCI/PCIe bridges, but the read always has to complete
synchronously and therefore has to flush all pending writes to a
device. If a write is held and followed by a delay, the delay
means nothing because the write may not have reached hardware
(maybe even not until the next read)
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'usr')
0 files changed, 0 insertions, 0 deletions