* [PATCH] nvme: Enable FUA
@ 2021-09-26 9:12 Jon Lin
2021-09-27 12:28 ` Stefan Agner
0 siblings, 1 reply; 3+ messages in thread
From: Jon Lin @ 2021-09-26 9:12 UTC (permalink / raw)
To: Bin Meng; +Cc: u-boot, zyf, Lin Shawn, Kever Yang, xxm, Jon Lin
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.
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;
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] nvme: Enable FUA
2021-09-26 9:12 [PATCH] nvme: Enable FUA Jon Lin
@ 2021-09-27 12:28 ` Stefan Agner
2021-09-27 13:25 ` Jon Lin
0 siblings, 1 reply; 3+ messages in thread
From: Stefan Agner @ 2021-09-27 12:28 UTC (permalink / raw)
To: Jon Lin; +Cc: Bin Meng, u-boot, zyf, Lin Shawn, Kever Yang, xxm
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?
--
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;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nvme: Enable FUA
2021-09-27 12:28 ` Stefan Agner
@ 2021-09-27 13:25 ` Jon Lin
0 siblings, 0 replies; 3+ messages in thread
From: Jon Lin @ 2021-09-27 13:25 UTC (permalink / raw)
To: Stefan Agner; +Cc: Bin Meng, u-boot, zyf, Lin Shawn, Kever Yang, xxm
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;
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-09-27 13:25 UTC | newest]
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2021-09-26 9:12 [PATCH] nvme: Enable FUA Jon Lin
2021-09-27 12:28 ` Stefan Agner
2021-09-27 13:25 ` Jon Lin
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