Re: [PATCH] thunderbolt: Disable CLx state for AMD Yellow Carp and Pink Sardine

[Sanjay R Mehta <sanmehta@amd.com>]

On 2/10/2023 7:47 PM, Mika Westerberg wrote:
> On Fri, Feb 10, 2023 at 07:32:13PM +0530, Sanjay R Mehta wrote:
>>
>>
>> On 2/10/2023 7:25 PM, Mika Westerberg wrote:
>>> Hi,
>>>
>>> On Fri, Feb 10, 2023 at 07:32:23AM -0600, Sanjay R Mehta wrote:
>>>> From: Sanjay R Mehta <sanju.mehta@amd.com>
>>>>
>>>> AMD Yellow Carp and Pink Sardine don't support CLx state,
>>>> hence disabling it.
>>>
>>> The lane adapters are supposed to announce whether CL-states are
>>> supported or not. Is that not the case with the AMD hardware?
>>
>> Yes Mika. it doesn't work for AMD hardware.
> 
> :-(
> 
> Okay can you then add a quirk for this to quirks.c?

Did you meant like below, is this fine?

diff --git a/drivers/thunderbolt/nhi.h b/drivers/thunderbolt/nhi.h
index b071802..138c649 100644
--- a/drivers/thunderbolt/nhi.h
+++ b/drivers/thunderbolt/nhi.h
@@ -49,6 +49,7 @@ struct tb_nhi_ops {
 };

 extern const struct tb_nhi_ops icl_nhi_ops;
+extern bool clx_enabled;

......
......

diff --git a/drivers/thunderbolt/quirks.c b/drivers/thunderbolt/quirks.c
index b5f2ec7..9ceef7c 100644
--- a/drivers/thunderbolt/quirks.c
+++ b/drivers/thunderbolt/quirks.c
@@ -63,4 +63,10 @@ void tb_check_quirks(struct tb_switch *sw)

                q->hook(sw);
        }
+
+       /*
+        * CLx is not supported on AMD USB4 Yellow Carp and Pink Sardine
platforms.
+        */
+       if (tb_switch_is_yellow_carp(sw->tb->nhi) ||
tb_switch_is_pink_sardine(sw->tb->nhi))
+               clx_enabled = false;
 }
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 363d712..d4492b5 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -26,7 +26,7 @@ struct nvm_auth_status {
        u32 status;
 };

-static bool clx_enabled = true;
+bool clx_enabled = true;
 module_param_named(clx, clx_enabled, bool, 0444);
 MODULE_PARM_DESC(clx, "allow low power states on the high-speed lanes
(default: true)");

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