From: Konrad Dybcio <konrad.dybcio@linaro.org>
To: Andy Gross <agross@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>,
Georgi Djakov <djakov@kernel.org>, Leo Yan <leo.yan@linaro.org>,
Evan Green <evgreen@chromium.org>
Cc: Marijn Suijten <marijn.suijten@somainline.org>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-clk@vger.kernel.org, linux-pm@vger.kernel.org,
Konrad Dybcio <konrad.dybcio@linaro.org>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Subject: [PATCH v2 05/22] interconnect: qcom: icc-rpm: Introduce keep_alive
Date: Fri, 09 Jun 2023 22:19:10 +0200 [thread overview]
Message-ID: <20230526-topic-smd_icc-v2-5-e5934b07d813@linaro.org> (raw)
In-Reply-To: <20230526-topic-smd_icc-v2-0-e5934b07d813@linaro.org>
The downstream kernel employs the concept of "keeping the bus alive"
by voting for the minimum (XO/19.2MHz) rate at all times on certain
(well, most) buses. This is a very important thing to have, as if we
either have a lackluster/wrong DT that doesn't specify a (high enough)
vote on a certain bus, we may lose access to the entire bus altogether.
This is very apparent when we only start introducing interconnect
support on a given platform and haven't yet introduced voting on all
peripherals.
The same can happen if we only have a single driver casting a vote on
a certain bus and that driver exits/crashes/suspends.
The keepalive vote is limited to the ACTIVE bucket, as keeping a
permanent vote on the SLEEP one could prevent the platform from properly
entering low power mode states.
Introduce the very same concept, with a slight twist: the vendor
kernel checks whether the rate is zero before setting the minimum
vote, but that's rather silly, as in doing so we're at the mercy
of CCF. Instead, explicitly clamp the rates to always be >= 19.2 MHz
for providers with keep_alive=true.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
drivers/interconnect/qcom/icc-rpm.c | 10 ++++++++++
drivers/interconnect/qcom/icc-rpm.h | 3 +++
2 files changed, 13 insertions(+)
diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index 6acc7686ed38..863e8ba1daa2 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -50,6 +50,8 @@
#define NOC_QOS_MODE_FIXED_VAL 0x0
#define NOC_QOS_MODE_BYPASS_VAL 0x2
+#define ICC_BUS_CLK_MIN_RATE 19200000ULL
+
static int qcom_icc_set_qnoc_qos(struct icc_node *src)
{
struct icc_provider *provider = src->provider;
@@ -380,6 +382,13 @@ static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
do_div(rate, src_qn->buswidth);
rate = min_t(u64, rate, LONG_MAX);
+ /*
+ * Downstream checks whether the requested rate is zero, but it makes little sense
+ * to vote for a value that's below the lower threshold, so let's not do so.
+ */
+ if (bucket == QCOM_ICC_BUCKET_WAKE && qp->keep_alive)
+ rate = max(ICC_BUS_CLK_MIN_RATE, rate);
+
if (qp->bus_clk_rate[i] == rate)
continue;
@@ -453,6 +462,7 @@ int qnoc_probe(struct platform_device *pdev)
for (i = 0; i < qp->num_bus_clks; i++)
qp->bus_clks[i].id = bus_clocks[i];
+ qp->keep_alive = desc->keep_alive;
qp->type = desc->type;
qp->qos_offset = desc->qos_offset;
diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
index ee705edf19dd..d2c04c400cad 100644
--- a/drivers/interconnect/qcom/icc-rpm.h
+++ b/drivers/interconnect/qcom/icc-rpm.h
@@ -33,6 +33,7 @@ enum qcom_icc_type {
* @bus_clk_rate: bus clock rate in Hz
* @bus_clks: the clk_bulk_data table of bus clocks
* @intf_clks: a clk_bulk_data array of interface clocks
+ * @keep_alive: whether to always keep a minimum vote on the bus clocks
* @is_on: whether the bus is powered on
*/
struct qcom_icc_provider {
@@ -45,6 +46,7 @@ struct qcom_icc_provider {
u64 bus_clk_rate[NUM_BUS_CLKS];
struct clk_bulk_data bus_clks[NUM_BUS_CLKS];
struct clk_bulk_data *intf_clks;
+ bool keep_alive;
bool is_on;
};
@@ -102,6 +104,7 @@ struct qcom_icc_desc {
const char * const *bus_clocks;
const char * const *intf_clocks;
size_t num_intf_clocks;
+ bool keep_alive;
bool no_clk_scaling;
enum qcom_icc_type type;
const struct regmap_config *regmap_cfg;
--
2.41.0
next prev parent reply other threads:[~2023-06-09 20:19 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-09 20:19 [PATCH v2 00/22] Restructure RPM SMD ICC Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 01/22] soc: qcom: smd-rpm: Add QCOM_SMD_RPM_STATE_NUM Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 02/22] soc: qcom: smd-rpm: Use tabs for defines Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 03/22] clk: qcom: smd-rpm: Move some RPM resources to the common header Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 04/22] clk: qcom: smd-rpm: Export clock scaling availability Konrad Dybcio
2023-06-10 11:35 ` Stephan Gerhold
2023-06-10 12:15 ` Konrad Dybcio
2023-06-10 18:53 ` Konrad Dybcio
2023-06-10 19:25 ` Stephan Gerhold
2023-06-10 19:39 ` Konrad Dybcio
2023-06-11 9:20 ` Stephan Gerhold
2023-06-12 12:51 ` Konrad Dybcio
2023-06-12 17:03 ` Konrad Dybcio
2023-06-09 20:19 ` Konrad Dybcio [this message]
2023-06-09 20:19 ` [PATCH v2 06/22] interconnect: qcom: icc-rpm: Allow negative QoS offset Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 07/22] interconnect: qcom: Fold smd-rpm.h into icc-rpm.h Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 08/22] interconnect: qcom: smd-rpm: Add rpmcc handling skeleton code Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 09/22] interconnect: qcom: Add missing headers in icc-rpm.h Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 10/22] interconnect: qcom: Define RPM bus clocks Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 11/22] interconnect: qcom: sdm660: Hook up RPM bus clk definitions Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 12/22] interconnect: qcom: msm8996: " Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 13/22] interconnect: qcom: qcs404: " Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 14/22] interconnect: qcom: msm8939: " Konrad Dybcio
2023-06-10 12:02 ` Stephan Gerhold
2023-06-09 20:19 ` [PATCH v2 15/22] interconnect: qcom: msm8916: " Konrad Dybcio
2023-06-10 12:02 ` Stephan Gerhold
2023-06-09 20:19 ` [PATCH v2 16/22] interconnect: qcom: qcm2290: " Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 17/22] interconnect: qcom: icc-rpm: Control bus rpmcc from icc Konrad Dybcio
2023-06-10 11:58 ` Stephan Gerhold
2023-06-10 12:14 ` Konrad Dybcio
2023-06-10 16:20 ` Stephan Gerhold
2023-06-10 17:54 ` Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 18/22] clk: qcom: smd-rpm: Separate out interconnect bus clocks Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 19/22] interconnect: qcom: icc-rpm: Fix bucket number Konrad Dybcio
2023-06-10 17:46 ` Stephan Gerhold
2023-06-10 17:53 ` Konrad Dybcio
2023-06-09 20:19 ` [PATCH v2 20/22] interconnect: qcom: icc-rpm: Set bandwidth on both contexts Konrad Dybcio
2023-06-10 18:00 ` Stephan Gerhold
2023-06-10 18:28 ` Konrad Dybcio
2023-06-10 18:43 ` Stephan Gerhold
2023-06-09 20:19 ` [PATCH v2 21/22] interconnect: qcom: icc-rpm: Set correct bandwidth through RPM bw req Konrad Dybcio
2023-06-10 18:46 ` Stephan Gerhold
2023-06-09 20:19 ` [PATCH v2 22/22] interconnect: qcom: icc-rpm: Fix bandwidth calculations Konrad Dybcio
2023-06-10 19:06 ` Stephan Gerhold
2023-06-10 19:09 ` Konrad Dybcio
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230526-topic-smd_icc-v2-5-e5934b07d813@linaro.org \
--to=konrad.dybcio@linaro.org \
--cc=agross@kernel.org \
--cc=andersson@kernel.org \
--cc=djakov@kernel.org \
--cc=dmitry.baryshkov@linaro.org \
--cc=evgreen@chromium.org \
--cc=leo.yan@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=marijn.suijten@somainline.org \
--cc=mturquette@baylibre.com \
--cc=sboyd@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).