On 2/22/2016 5:41 PM, Dan Williams wrote: > On Mon, Feb 22, 2016 at 2:22 PM, Linda Knippers <linda.knippers@xxxxxxx> wrote: >> >> >> On 2/20/2016 5:46 PM, Dan Williams wrote: >>> The original format of these commands from the "NVDIMM DSM Interface >>> Example" [1] are superseded by the ACPI 6.1 definition of the "NVDIMM Root >>> Device _DSMs" [2]. >>> >>> [1]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf >>> [2]: http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf >>> "9.20.7 NVDIMM Root Device _DSMs" >>> >>> Changes include: >>> 1/ New 'restart' fields in ars_status, unfortunately these are >>> implemented in the middle of the existing definition so this change >>> is not backwards compatible. The expectation is that shipping >>> platforms will only ever support the ACPI 6.1 definition. >> >> I agree with that. >> >>> >>> 2/ New status values for ars_start ('busy') and ars_status ('overflow'). >>> >>> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> >>> Cc: Linda Knippers <linda.knippers@xxxxxxx> >>> Cc: <stable@xxxxxxxxxxxxxxx> >>> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> >>> --- > [..] >>> diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c >>> index 99953b34fa1d..5d28e9405f32 100644 >>> --- a/drivers/nvdimm/bus.c >>> +++ b/drivers/nvdimm/bus.c >>> @@ -382,14 +382,14 @@ static const struct nd_cmd_desc __nd_cmd_bus_descs[] = { >>> [ND_CMD_ARS_CAP] = { >>> .in_num = 2, >>> .in_sizes = { 8, 8, }, >>> - .out_num = 2, >>> - .out_sizes = { 4, 4, }, >>> + .out_num = 4, >>> + .out_sizes = { 4, 4, 4, 4, }, >> >> The status was 4 bytes but now it's 2 bytes of status and 2 bytes of extended >> status. Where things are didn't actually change but should the two status >> fields be defined separately to match the spec? It would save some shifting and >> anding. Maybe a nit... > > For this patch, since I'm tagging it for -stable and ndctl.h is > exported to userspace, I don't want "status" to have a different > meaning depending on which version of the kernel header an application > happened to be compiled against. I think we're stuck with the unified > u32. I was originally thinking that this would be a good time to change since some of the data formats were changing too but I've reconsidered based on some other draft/example DSMs I've seen. The one thing that's consistent is that there are 4 bytes of status. Sometimes the bytes are split into sub-status fields but not necessarily into 2 2-byte chunks. It's more flexible the way it is. -- ljk -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
