Re: [PATCH] acpi/nfit: Fix command-supported detection

[Pandel, Sujith]

Hi Dan,

On 12-Jan-19 5:29 AM, Dan Williams wrote:
> The _DSM function number validation only happens to succeed when the
> generic Linux command number translation corresponds with a
> DSM-family-specific function number. This breaks NVDIMM-N
> implementations that correctly implement _LSR, _LSW, and _LSI, but do
> not happen to publish support for DSM function numbers 4, 5, and 6.
>
> Recall that the support for _LS{I,R,W} family of methods results in the
> DIMM being marked as supporting those command numbers at
> acpi_nfit_register_dimms() time. The DSM function mask is only used for
> ND_CMD_CALL support of non-NVDIMM_FAMILY_INTEL devices.
>
> Fixes: 31eca76ba2fc ("nfit, libnvdimm: limited/whitelisted dimm command...")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Link: https://github.com/pmem/ndctl/issues/78
> Reported-by: Sujith Pandel <sujith_pandel@xxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> Sujith, this is a larger change than what you originally tested, but it
> should behave the same. I wanted to consolidate all the code that
> handles Linux command number to DIMM _DSM function number translation.
>
> If you have a chance to re-test with this it would be much appreciated.
>
> Thanks for the report!
Re-verified by applying this patch over LTS kernel-4.20.2 with ndctl v62.
namespace creation and modification works fine on Dell NVDIMM-Ns.
Thanks for helping me on this!

Tested-by: Sujith Pandel <sujith_pandel@xxxxxxxx>