From 77037bcf25d536efa551f0ae4edf1a65f8852b03 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Mon, 8 Jul 2019 14:42:16 +0100 Subject: [PATCH] UPSTREAM: firmware: arm_scmi: Use asynchronous CLOCK_RATE_SET when possible CLOCK_PROTOCOL_ATTRIBUTES provides attributes to indicate the maximum number of pending asynchronous clock rate changes supported by the platform. If it's non-zero, then we should be able to use asynchronous clock rate set for any clocks until the maximum limit is reached. Tracking the current count of pending asynchronous clock set rate requests, we can decide if the incoming/new request for clock set rate can be handled asynchronously or not until the maximum limit is reached. Change-Id: I958da7f1990ef773e26f182b59af26c5717ebd61 Cc: linux-clk@vger.kernel.org Reviewed-by: Stephen Boyd Signed-off-by: Sudeep Holla Signed-off-by: Tao Huang (cherry picked from commit 2bc06ffa0635e99cd4d88d6f6fe5bb4e4b9e50f1) --- drivers/firmware/arm_scmi/clock.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c index da0d1ffad6c9..7ce3013c44c9 100644 --- a/drivers/firmware/arm_scmi/clock.c +++ b/drivers/firmware/arm_scmi/clock.c @@ -56,7 +56,7 @@ struct scmi_msg_resp_clock_describe_rates { struct scmi_clock_set_rate { __le32 flags; #define CLOCK_SET_ASYNC BIT(0) -#define CLOCK_SET_DELAYED BIT(1) +#define CLOCK_SET_IGNORE_RESP BIT(1) #define CLOCK_SET_ROUND_UP BIT(2) #define CLOCK_SET_ROUND_AUTO BIT(3) __le32 id; @@ -67,6 +67,7 @@ struct scmi_clock_set_rate { struct clock_info { int num_clocks; int max_async_req; + atomic_t cur_async_req; struct scmi_clock_info *clk; }; @@ -221,21 +222,33 @@ static int scmi_clock_rate_set(const struct scmi_handle *handle, u32 clk_id, u64 rate) { int ret; + u32 flags = 0; struct scmi_xfer *t; struct scmi_clock_set_rate *cfg; + struct clock_info *ci = handle->clk_priv; ret = scmi_xfer_get_init(handle, CLOCK_RATE_SET, SCMI_PROTOCOL_CLOCK, sizeof(*cfg), 0, &t); if (ret) return ret; + if (ci->max_async_req && + atomic_inc_return(&ci->cur_async_req) < ci->max_async_req) + flags |= CLOCK_SET_ASYNC; + cfg = t->tx.buf; - cfg->flags = cpu_to_le32(0); + cfg->flags = cpu_to_le32(flags); cfg->id = cpu_to_le32(clk_id); cfg->value_low = cpu_to_le32(rate & 0xffffffff); cfg->value_high = cpu_to_le32(rate >> 32); - ret = scmi_do_xfer(handle, t); + if (flags & CLOCK_SET_ASYNC) + ret = scmi_do_xfer_with_response(handle, t); + else + ret = scmi_do_xfer(handle, t); + + if (ci->max_async_req) + atomic_dec(&ci->cur_async_req); scmi_xfer_put(handle, t); return ret;