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References: <20231102075853.1320710-1-xinglong.yang@cixtech.com>
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From:   sean yang <seanyang230@gmail.com>
Date:   Thu, 2 Nov 2023 17:54:37 +0800
Message-ID: <CADGqjFKS9ytGOdvrcr=JuggRFW_1bgLVn-EJTbjoa4wSwgNhHQ@mail.gmail.com>
Subject: Fwd: [PATCH v2] firmware: arm_scmi: Refrain set operations of perf
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
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---------- Forwarded message ---------
=E5=8F=91=E4=BB=B6=E4=BA=BA=EF=BC=9A xinglong.yang <seanyang230@gmail.com>
Date: 2023=E5=B9=B411=E6=9C=882=E6=97=A5=E5=91=A8=E5=9B=9B 15:59
Subject: [PATCH v2] firmware: arm_scmi: Refrain set operations of perf
To: <xinglong.yang@cixtech.com>, <sudeep.holla@arm.com>,
<cristian.marussi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>


Refrain from trying to take the SET operation where the set_* operations
are not supported, because: (1.) avoid unneeded SCMI exchanges, (2.)
avoids to trust the FW reply blindly.

Signed-off-by: xinglong.yang <xinglong.yang@cixtech.com>
---
 drivers/firmware/arm_scmi/perf.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/p=
erf.c
index 431bda9165c3..3bcdef91ed5c 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -377,6 +377,9 @@ static int scmi_perf_limits_set(const struct
scmi_protocol_handle *ph,
        if (IS_ERR(dom))
                return PTR_ERR(dom);

+       if (!dom->set_limits)
+               return -EOPNOTSUPP;
+
        if (PROTOCOL_REV_MAJOR(pi->version) >=3D 0x3 && !max_perf && !min_p=
erf)
                return -EINVAL;

@@ -473,6 +476,9 @@ static int scmi_perf_level_set(const struct
scmi_protocol_handle *ph,
        if (IS_ERR(dom))
                return PTR_ERR(dom);

+       if (!dom->set_perf)
+               return -EOPNOTSUPP;
+
        if (dom->fc_info && dom->fc_info[PERF_FC_LEVEL].set_addr) {
                struct scmi_fc_info *fci =3D &dom->fc_info[PERF_FC_LEVEL];

--
2.42.0