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 stefan@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.lin@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;