diff options
| -rw-r--r-- | drivers/nvdimm/pmem.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 8e09c544d892..f798899338ed 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -103,6 +103,20 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, flush_dcache_page(page); } } else { + /* + * Note that we write the data both before and after + * clearing poison. The write before clear poison + * handles situations where the latest written data is + * preserved and the clear poison operation simply marks + * the address range as valid without changing the data. + * In this case application software can assume that an + * interrupted write will either return the new good + * data or an error. + * + * However, if pmem_clear_poison() leaves the data in an + * indeterminate state we need to perform the write + * after clear poison. + */ flush_dcache_page(page); memcpy_to_pmem(pmem_addr, mem + off, len); if (unlikely(bad_pmem)) { |