Some platform misreported the support of FastChannel when queried: ignore
that bit on selected platforms.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
Match features has to be set-up properly before upstreaming this.
Ideally the out-of-spec firmware should be matched with a quirk matching
pattern based on Vendor/SubVendor/ImplVersion....but it is NOT clear if the
platform at hand will ship with future fixed firmwares where the ImplVersion
field is properly handled.
If we cannot be sure about that, we should fallback to a compatible match.

v1 -> v2
- use multiple compats quirks syntax

RFC->V1
- fix QUIRKS conditions
---
 drivers/firmware/arm_scmi/driver.c | 8 ++++++++
 drivers/firmware/arm_scmi/quirks.c | 3 +++
 drivers/firmware/arm_scmi/quirks.h | 1 +
 3 files changed, 12 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index ffaa68cdf644..3b363bda2b1e 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1904,6 +1904,13 @@ struct scmi_msg_resp_desc_fc {
 	__le32 db_preserve_hmask;
 };
 
+#define QUIRK_PERF_FC_FORCE						\
+	({								\
+		if (pi->proto->id == SCMI_PROTOCOL_PERF &&		\
+		    message_id == 0x8 /* PERF_LEVEL_GET */)		\
+			attributes |= BIT(0);				\
+	})
+
 static void
 scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
 			     u8 describe_id, u32 message_id, u32 valid_size,
@@ -1924,6 +1931,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
 
 	/* Check if the MSG_ID supports fastchannel */
 	ret = scmi_protocol_msg_check(ph, message_id, &attributes);
+	SCMI_QUIRK(perf_level_get_fc_force, QUIRK_PERF_FC_FORCE);
 	if (ret || !MSG_SUPPORTS_FASTCHANNEL(attributes)) {
 		dev_dbg(ph->dev,
 			"Skip FC init for 0x%02X/%d  domain:%d - ret:%d\n",
diff --git a/drivers/firmware/arm_scmi/quirks.c b/drivers/firmware/arm_scmi/quirks.c
index 120ac933ed2e..64a5809da20b 100644
--- a/drivers/firmware/arm_scmi/quirks.c
+++ b/drivers/firmware/arm_scmi/quirks.c
@@ -168,6 +168,8 @@ struct scmi_quirk {
 
 /* Global Quirks Definitions */
 DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
+DEFINE_SCMI_QUIRK(perf_level_get_fc_force,
+		  "bad-vend", NULL, "0x20000-", "bad-compat", "bad-compat-2");
 
 /*
  * Quirks Pointers Array
@@ -177,6 +179,7 @@ DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
  */
 static struct scmi_quirk *scmi_quirks_table[] = {
 	__DECLARE_SCMI_QUIRK_ENTRY(clock_rates_triplet_out_of_spec),
+	__DECLARE_SCMI_QUIRK_ENTRY(perf_level_get_fc_force),
 	NULL
 };
 
diff --git a/drivers/firmware/arm_scmi/quirks.h b/drivers/firmware/arm_scmi/quirks.h
index 7fdc496c94c7..a71fde85a527 100644
--- a/drivers/firmware/arm_scmi/quirks.h
+++ b/drivers/firmware/arm_scmi/quirks.h
@@ -47,5 +47,6 @@ static inline void scmi_quirks_enable(struct device *dev, const char *vend,
 
 /* Quirk delarations */
 DECLARE_SCMI_QUIRK(clock_rates_triplet_out_of_spec);
+DECLARE_SCMI_QUIRK(perf_level_get_fc_force);
 
 #endif /* _SCMI_QUIRKS_H */
-- 
2.47.0

On Fri, Apr 25, 2025 at 01:52:50PM +0100, Cristian Marussi wrote:
> Some platform misreported the support of FastChannel when queried: ignore
> that bit on selected platforms.
> 
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
> Match features has to be set-up properly before upstreaming this.
> Ideally the out-of-spec firmware should be matched with a quirk matching
> pattern based on Vendor/SubVendor/ImplVersion....but it is NOT clear if the
> platform at hand will ship with future fixed firmwares where the ImplVersion
> field is properly handled.
> If we cannot be sure about that, we should fallback to a compatible match.
> 
> v1 -> v2
> - use multiple compats quirks syntax
> 
> RFC->V1
> - fix QUIRKS conditions

>  /* Global Quirks Definitions */
>  DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
> +DEFINE_SCMI_QUIRK(perf_level_get_fc_force,
> +		  "bad-vend", NULL, "0x20000-", "bad-compat", "bad-compat-2");

Still works when matching on vendor and version (and/or machine or SoC
compatible):

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>

I think we can go ahead and merge this based on vendor and version
"0x20000-".

Depending on what Sibi finds out, or if it turns out to be needed, we
can always add an upper version bound later.

Johan

On Sun, Apr 27, 2025 at 04:46:47PM +0200, Johan Hovold wrote:
> On Fri, Apr 25, 2025 at 01:52:50PM +0100, Cristian Marussi wrote:
> > Some platform misreported the support of FastChannel when queried: ignore
> > that bit on selected platforms.
> > 
> > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> > ---
> > Match features has to be set-up properly before upstreaming this.
> > Ideally the out-of-spec firmware should be matched with a quirk matching
> > pattern based on Vendor/SubVendor/ImplVersion....but it is NOT clear if the
> > platform at hand will ship with future fixed firmwares where the ImplVersion
> > field is properly handled.
> > If we cannot be sure about that, we should fallback to a compatible match.
> > 
> > v1 -> v2
> > - use multiple compats quirks syntax
> > 
> > RFC->V1
> > - fix QUIRKS conditions
> 
> >  /* Global Quirks Definitions */
> >  DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
> > +DEFINE_SCMI_QUIRK(perf_level_get_fc_force,
> > +		  "bad-vend", NULL, "0x20000-", "bad-compat", "bad-compat-2");
> 
> Still works when matching on vendor and version (and/or machine or SoC
> compatible):
> 
> Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
> Tested-by: Johan Hovold <johan+linaro@kernel.org>
> 
> I think we can go ahead and merge this based on vendor and version
> "0x20000-".
> 
> Depending on what Sibi finds out, or if it turns out to be needed, we
> can always add an upper version bound later.

Sure...sounds good.
Please post your final tested patch on top on my V3 as said elsewhere.

Thanks,
Cristian