[PATCH 1/1][SRU][OEM-5.10] UBUNTU: SAUCE: platform/x86: intel_pmc: Ignore GBE LTR on Tiger Lake platforms

[Andrea Righi]

On Mon, Mar 15, 2021 at 02:53:28PM +0800, AceLan Kao wrote:
> From: "David E. Box" <david.e.box at linux.intel.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1919116
> 
> Due to a HW limitation, the Latency Tolerance Reporting (LTR) value
> programmed in the Tiger Lake GBE controller is not large enough to allow
> the platform to enter Package C10, which in turn prevents the platform from
> achieving its low power target during suspend-to-idle.  Ignore the GBE LTR
> value on Tiger Lake. LTR ignore functionality is currently performed solely
> by a debugfs write call. Split out the LTR code into its own function that
> can be called by both the debugfs writer and by this work around.
> 
> Signed-off-by: David E. Box <david.e.box at linux.intel.com>
> Reviewed-by: Sasha Neftin <sasha.neftin at intel.com>
> Cc: intel-wired-lan at lists.osuosl.org
> (cherry picked from
> https://patchwork.kernel.org/project/platform-driver-x86/patch/20210305190608.1834164-1-david.e.box@linux.intel.com/)
> Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao at canonical.com>
> ---
>  drivers/platform/x86/intel_pmc_core.c | 55 ++++++++++++++++++++-------
>  1 file changed, 42 insertions(+), 13 deletions(-)

...
> +	/*
> +	 * On TGL, due to a hardware limitation, the GBE LTR blocks PC10 when
> +	 * a cable is attached. Tell the PMC to ignore it.
> +	 */
> +	if (pmcdev->map == &tgl_reg_map) {

Someone on the list suggested: if (pmcdev->map >= &tgl_reg_map)

Should we include also this change?

Thanks,
-Andrea

> +		dev_dbg(&pdev->dev, "ignoring GBE LTR\n");
> +		quirk_ltr_ignore(1U << 3);
> +	}
> +
>  	pmc_core_dbgfs_register(pmcdev);
>  
>  	device_initialized = true;
> -- 
> 2.25.1
> 
> 
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