On 2021/9/27 20:28, Stefan Agner wrote:
On 2021-09-26 11:12, Jon Lin wrote:
Most NVME devcies maintain data in internal cache for an uncertain
times, and u-boot has no method to force NVME to flush cache.
So this patch adds FUA to avoid data loss caused by power off after data
programming.
Maybe worth mentioning that FUA stands for Force Unit Access and makes
sure that data has been written to non-volatile storage before command
completion.
It seems to me that volatile cache needs to be explicitly enabled by the
Volatile Write Cache feature. But I guess it could be already enabled by
earlier firmware/on reboot? Setting the FUA bit will make certain that
data land on non-volatile storage in any case. So:
Reviewed-by: Stefan Agner <ste...@agner.ch>
Out of curiosity, has this been a problem in a real world situation?
We are trying to interact with the host computer in the device u-boot
stage, involving nvme
upgrade and device reset. When the two progress are continuous, there
are corresponding problems.
--
Stefan
Signed-off-by: Jon Lin <jon....@rock-chips.com>
---
drivers/nvme/nvme.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index f6465ea7f4..5d05cb6e9e 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -761,6 +761,9 @@ static ulong nvme_blk_rw(struct udevice *udev,
lbaint_t blknr,
c.rw.appmask = 0;
c.rw.metadata = 0;
+ /* Always enable FUA for data integrity */
+ c.rw.control |= NVME_RW_FUA;
+
while (total_lbas) {
if (total_lbas < lbas) {
lbas = (u16)total_lbas;
