firmware: arm_scmi: Set clock latency to U32_MAX if it is not supported

As per the spec, the clock_enable_delay is the worst case latency
incurred by the platform to enable the clock. The value of 0 indicates
that the platform doesn't support the same and must be considered as
maximum latency for practical purposes.

Currently the value of 0 is assigned as is and is propogated to the clock
framework which can assume that the clock can support atomic enable operation.

Link: https://lore.kernel.org/r/20220428122913.1654821-1-sudeep.holla@arm.com
Fixes: 18f295b758b2 ("firmware: arm_scmi: Add support for clock_enable_latency")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 7a031afff389f8f38ef5c99df4cf274f7fac765c..81f7397008934cfb636b9d220bb8ebbe302cbb41 100644 (file)
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/limits.h>
 #include <linux/sort.h>
 
 #include "protocols.h"
@@ -128,12 +129,13 @@ static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
 
        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
+               u32 latency = 0;
                attributes = le32_to_cpu(attr->attributes);
                strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
                /* Is optional field clock_enable_latency provided ? */
                if (t->rx.len == sizeof(*attr))
-                       clk->enable_latency =
-                               le32_to_cpu(attr->clock_enable_latency);
+                       latency = le32_to_cpu(attr->clock_enable_latency);
+               clk->enable_latency = latency ? : U32_MAX;
        }
 
        ph->xops->xfer_put(ph, t);