| Message ID | 20231201164005.135912-1-huaisheng.ye@intel.com |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cxl/core/mbox: get next_persistent_bytes by next_persistent_cap | expand |
Huaisheng Ye wrote: > According to CXL 2.0 8.2.9.5.2.1 table 176, the next Persistent > Bytes should be calculated by next Persistent Capacity. > > Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com> Do we have a fixes tag for this? Was there a bug associated with this find? Ira > --- > drivers/cxl/core/mbox.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index 36270dcfb42e..7b8ec73ca37f 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -1069,7 +1069,7 @@ static int cxl_mem_get_partition_info(struct cxl_memdev_state *mds) > mds->next_volatile_bytes = > le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER; > mds->next_persistent_bytes = > - le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER; > + le64_to_cpu(pi.next_persistent_cap) * CXL_CAPACITY_MULTIPLIER; > > return 0; > } > -- > 2.39.0 >
On 2023-12-06 05:48, Ira Weiny wrote: > Huaisheng Ye wrote: >> According to CXL 2.0 8.2.9.5.2.1 table 176, the next Persistent >> Bytes should be calculated by next Persistent Capacity. >> >> Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com> > Do we have a fixes tag for this? Was there a bug associated with this > find? > > Ira Hi Ira, This bug could be found in cxl-next branch. It looks like just cxl-pci would calculate next_persistent_bytes during probe. Afterwards, it will no longer be accessed by current cxl drivers. For v78 ndctl, cxl_cmd_partition_get_next_persistent_size is calculated from next_persistent, which is correct. May I have your Reviewed-by? Huaisheng
Huaisheng Ye wrote: > > > On 2023-12-06 05:48, Ira Weiny wrote: > > Huaisheng Ye wrote: > >> According to CXL 2.0 8.2.9.5.2.1 table 176, the next Persistent > >> Bytes should be calculated by next Persistent Capacity. > >> > >> Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com> > > Do we have a fixes tag for this? Was there a bug associated with this > > find? > > > > Ira > > Hi Ira, Hey... First off thanks for the patch. This is obviously something which is wrong. I'm just trying to get more details about how much work should be done to fix this. > > This bug could be found in cxl-next branch. This looks like it has been a bug for a while. 59f8d1510739e (Dan Williams 2023-06-14 18:30:02 -0700 1071) mds->next_persistent_bytes = 4faf31b43468c (Dan Williams 2021-09-08 22:12:32 -0700 1072) le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER; Both of those commits were refactoring so the fixes goes back a bit more. My question is: what problem is this causing for the user and should we ID which commit's this fixes for potential backporting to stable kernels? Do you have that information? > It looks like just cxl-pci would calculate next_persistent_bytes during > probe. Afterwards, it will no longer be accessed by current cxl drivers. > > For v78 ndctl, cxl_cmd_partition_get_next_persistent_size is calculated from > next_persistent, which is correct. This too seems to be old behavior. 4f588b964dccf (Alison Schofield 2022-02-22 11:56:03 -0800 4142)cxl_cmd_partition_get_next_persistent_size(struct cxl_cmd *cmd) > > May I have your Reviewed-by? Not yet. I want to know should this be backported and what problems this causes. The next values are not going to take effect until the next reboot/reset of the device. So they are basically informational, Right?. Is that why you did not add a fixes to the patch? If so mention that a fixes is not needed. If not, explain why this is something a user might see and lets figure out what fixes tags to add so this gets backported. Thanks, Ira
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 36270dcfb42e..7b8ec73ca37f 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -1069,7 +1069,7 @@ static int cxl_mem_get_partition_info(struct cxl_memdev_state *mds) mds->next_volatile_bytes = le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER; mds->next_persistent_bytes = - le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER; + le64_to_cpu(pi.next_persistent_cap) * CXL_CAPACITY_MULTIPLIER; return 0; }
According to CXL 2.0 8.2.9.5.2.1 table 176, the next Persistent Bytes should be calculated by next Persistent Capacity. Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com> --- drivers/cxl/core/mbox.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)