[RFC v6 0/2] Add SDHC interconnect bandwidth scaling

[RFC v6 0/2] Add SDHC interconnect bandwidth scaling

[Pradeep P V K]

Add interconnect bandwidths for SDHC driver using OPP framework that
is required by SDHC driver based on the clock frequency and bus width
of the card. Otherwise, the system clocks may run at minimum clock
speed and thus affecting the performance.

This change is based on
[RFC] mmc: host: sdhci-msm: Use the interconnect API
(https://lkml.org/lkml/2018/10/11/499) and

[PATCH v6] Introduce Bandwidth OPPs for interconnects
(https://lkml.org/lkml/2019/12/6/740)

Pradeep P V K (2):
  mmc: sdhci-msm: Add interconnect bus bandwidth scaling support
  dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings

 .../devicetree/bindings/mmc/sdhci-msm.txt          |  18 ++
 drivers/mmc/host/sdhci-msm.c                       | 240 ++++++++++++++++++++-
 2 files changed, 254 insertions(+), 4 deletions(-)

-- 
RFC v5 -> v6:
- Added Rob's Acked-by and Bjorn Reviewed-by for the DT patch.
- Added new goto jump tag to put both icc paths.
- Removed bus vote data error check and added is_null check.
- Addressed minor code style comments.

[RFC v6 1/2] mmc: sdhci-msm: Add interconnect bus bandwidth scaling support

[Pradeep P V K]

Add interconnect bandwidths for SDHC driver using OPP framework that
is required by SDHC driver based on the clock frequency and bus width
of the card. Otherwise, the system clocks may run at minimum clock
speed and thus affecting the performance.

This change is based on
[RFC] mmc: host: sdhci-msm: Use the interconnect API
(https://lkml.org/lkml/2018/10/11/499) and

[PATCH v6] Introduce Bandwidth OPPs for interconnects
(https://lkml.org/lkml/2019/12/6/740)

Co-developed-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Co-developed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Co-developed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Co-developed-by: Pradeep P V K <ppvk@codeaurora.org>
Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
---

RFC v5 -> v6:
- Added new goto jump tag to put both icc paths.
- Removed bus vote data error check and added is_null check.
- Addressed minor code style comments.

 drivers/mmc/host/sdhci-msm.c | 240 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 236 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 09ff731..469db65 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -11,8 +11,10 @@
 #include <linux/mmc/mmc.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
+#include <linux/interconnect.h>
 #include <linux/iopoll.h>
 #include <linux/regulator/consumer.h>
+#include <linux/pm_opp.h>
 
 #include "sdhci-pltfm.h"
 #include "cqhci.h"
@@ -234,6 +236,12 @@ struct sdhci_msm_variant_info {
 	const struct sdhci_msm_offset *offset;
 };
 
+struct sdhci_msm_bus_vote_data {
+	struct icc_path *sdhc_to_ddr;
+	struct icc_path *cpu_to_sdhc;
+	u32 curr_freq;
+};
+
 struct sdhci_msm_host {
 	struct platform_device *pdev;
 	void __iomem *core_mem;	/* MSM SDCC mapped address */
@@ -260,8 +268,11 @@ struct sdhci_msm_host {
 	bool use_cdr;
 	u32 transfer_mode;
 	bool updated_ddr_cfg;
+	struct sdhci_msm_bus_vote_data *bus_vote_data;
 };
 
+static void sdhci_msm_bus_voting(struct sdhci_host *host, bool enable);
+
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -1581,6 +1592,7 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
 
 	msm_set_clock_rate_for_bus_mode(host, clock);
 out:
+	sdhci_msm_bus_voting(host, !!clock);
 	__sdhci_msm_set_clock(host, clock);
 }
 
@@ -1823,6 +1835,210 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
 }
 
+/*
+ * Returns required bandwidth in Bytes per Sec
+ */
+static unsigned long sdhci_get_bw_required(struct sdhci_host *host,
+					struct mmc_ios *ios)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		return msm_host->clk_rate / 8;
+	case MMC_BUS_WIDTH_4:
+		return msm_host->clk_rate / 2;
+	case MMC_BUS_WIDTH_8:
+		break;
+	}
+	return msm_host->clk_rate;
+}
+
+/*
+ * Helper function to parse the exact OPP node
+ * Returns OPP pointer on success else NULL on error
+ */
+static struct dev_pm_opp
+		*sdhci_msm_find_opp_for_freq(struct sdhci_msm_host *msm_host,
+							unsigned long bw)
+{
+	struct dev_pm_opp *opp;
+	struct sdhci_host *host = mmc_priv(msm_host->mmc);
+	unsigned int freq = bw;
+	struct device *dev = &msm_host->pdev->dev;
+
+
+	if (!freq)
+		opp = dev_pm_opp_find_peak_bw_floor(dev, &freq);
+	else
+		opp = dev_pm_opp_find_peak_bw_exact(dev, freq, true);
+
+	/* Max bandwidth vote */
+	if (PTR_ERR(opp) == -ERANGE && freq > sdhci_msm_get_max_clock(host))
+		opp = dev_pm_opp_find_peak_bw_ceil(dev, &bw);
+
+	if (IS_ERR(opp)) {
+		dev_err(dev, "Failed to find OPP for freq:%u err:%ld\n",
+				freq, PTR_ERR(opp));
+		return NULL;
+	}
+	return opp;
+}
+
+/*
+ * This function sets the interconnect bus bandwidth
+ * vote based on bw (bandwidth) argument.
+ */
+#define BUS_INTERCONNECT_PATHS 2 /* 1. sdhc -> ddr 2. cpu -> sdhc */
+static void sdhci_msm_bus_set_vote(struct sdhci_host *host,
+						unsigned int bw)
+{
+	int i, err;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct sdhci_msm_bus_vote_data *vote_data = msm_host->bus_vote_data;
+	struct device *dev = &msm_host->pdev->dev;
+	struct dev_pm_opp *opp;
+	unsigned long freq = bw;
+	unsigned long peak_bw[BUS_INTERCONNECT_PATHS] = {0};
+	unsigned long avg_bw[BUS_INTERCONNECT_PATHS] = {0};
+
+	if (bw == vote_data->curr_freq)
+		return;
+
+	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++) {
+		opp = sdhci_msm_find_opp_for_freq(msm_host, freq);
+		if (opp) {
+			avg_bw[i] = dev_pm_opp_get_bw(opp, &peak_bw[i]);
+			freq += 1; /* Next bandwidth vote */
+			dev_pm_opp_put(opp);
+		}
+	}
+	pr_debug("%s: freq:%d sdhc_to_ddr avg_bw:%lu peak_bw:%lu cpu_to_sdhc avg_bw:%lu peak_bw:%lu\n",
+			mmc_hostname(host->mmc), bw, avg_bw[0], peak_bw[0],
+				avg_bw[1], peak_bw[1]);
+	err = icc_set_bw(vote_data->sdhc_to_ddr, 0, peak_bw[0]);
+	if (err) {
+		dev_err(dev, "icc_set() failed for 'sdhc-ddr' path err:%d\n",
+			err);
+		return;
+	}
+	err = icc_set_bw(vote_data->cpu_to_sdhc, 0, peak_bw[1]);
+	if (err) {
+		dev_err(dev, "icc_set() failed for 'cpu-sdhc' path err:%d\n",
+			err);
+		return;
+	}
+	vote_data->curr_freq = bw;
+}
+
+/*
+ * Helper function to register for OPP and interconnect
+ * frameworks.
+ */
+static struct sdhci_msm_bus_vote_data
+		*sdhci_msm_bus_register(struct sdhci_msm_host *host,
+				struct platform_device *pdev)
+{
+	struct sdhci_msm_bus_vote_data *vote_data;
+	struct device *dev = &pdev->dev;
+	int i, err;
+	struct icc_path *icc_paths[BUS_INTERCONNECT_PATHS];
+	const char *path_names[] = {
+		"sdhc-ddr",
+		"cpu-sdhc",
+	};
+
+	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++)
+		icc_paths[i] = of_icc_get(&pdev->dev, path_names[i]);
+
+	if (!icc_paths[0] && !icc_paths[1]) {
+		dev_info(&pdev->dev, "ICC DT property is missing.Skip vote!!\n");
+		return NULL;
+	}
+
+	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++) {
+		if (!icc_paths[i]) {
+			dev_err(&pdev->dev, "interconnect path '%s' is not configured\n",
+					path_names[i]);
+			err = -EINVAL;
+			goto handle_err;
+		}
+		if (IS_ERR(icc_paths[i])) {
+			err = PTR_ERR(icc_paths[i]);
+
+			if (err != -EPROBE_DEFER)
+				dev_err(&pdev->dev, "interconnect path '%s' is invalid:%d\n",
+					path_names[i], err);
+			goto handle_err;
+		}
+	}
+
+	err = dev_pm_opp_of_add_table(dev);
+	if (err) {
+		if (err == -ENODEV || err == -ENODATA)
+			dev_err(dev, "OPP dt properties missing:%d\n", err);
+		else
+			dev_err(dev, "OPP registration failed:%d\n", err);
+		goto put_icc;
+	}
+
+	vote_data = devm_kzalloc(dev, sizeof(*vote_data), GFP_KERNEL);
+	if (!vote_data) {
+		err = -ENOMEM;
+		goto put_icc;
+	}
+	vote_data->sdhc_to_ddr = icc_paths[0];
+	vote_data->cpu_to_sdhc = icc_paths[1];
+	return vote_data;
+
+handle_err:
+	if (err) {
+		int other = (i == 0) ? 1 : 0;
+
+		if (!IS_ERR_OR_NULL(icc_paths[other]))
+			icc_put(icc_paths[other]);
+	}
+	return ERR_PTR(err);
+
+put_icc:
+	if (err) {
+		for (i = 0; i < BUS_INTERCONNECT_PATHS; i++)
+			icc_put(icc_paths[i]);
+	}
+	return ERR_PTR(err);
+}
+
+static void sdhci_msm_bus_unregister(struct device *dev,
+				struct sdhci_msm_host *host)
+{
+	struct sdhci_msm_bus_vote_data *vote_data = host->bus_vote_data;
+
+	if (!vote_data)
+		return;
+
+	icc_put(vote_data->sdhc_to_ddr);
+	icc_put(vote_data->cpu_to_sdhc);
+}
+
+static void sdhci_msm_bus_voting(struct sdhci_host *host, bool enable)
+{
+	struct mmc_ios *ios = &host->mmc->ios;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	unsigned int bw;
+
+	if (!msm_host->bus_vote_data)
+		return;
+
+	if (enable) {
+		bw = sdhci_get_bw_required(host, ios);
+		sdhci_msm_bus_set_vote(host, bw);
+	} else
+		sdhci_msm_bus_set_vote(host, 0);
+}
+
 static void sdhci_msm_reset(struct sdhci_host *host, u8 mask)
 {
 	if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL))
@@ -1992,11 +2208,20 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 		dev_warn(&pdev->dev, "TCXO clk not present (%d)\n", ret);
 	}
 
+	msm_host->bus_vote_data = sdhci_msm_bus_register(msm_host, pdev);
+	if (IS_ERR(msm_host->bus_vote_data)) {
+		ret = PTR_ERR(msm_host->bus_vote_data);
+		dev_err(&pdev->dev, "Bus registration failed (%d)\n", ret);
+		goto clk_disable;
+	}
+
+	sdhci_msm_bus_voting(host, true);
+
 	if (!msm_host->mci_removed) {
 		msm_host->core_mem = devm_platform_ioremap_resource(pdev, 1);
 		if (IS_ERR(msm_host->core_mem)) {
 			ret = PTR_ERR(msm_host->core_mem);
-			goto clk_disable;
+			goto bus_unregister;
 		}
 	}
 
@@ -2071,7 +2296,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
 	if (msm_host->pwr_irq < 0) {
 		ret = msm_host->pwr_irq;
-		goto clk_disable;
+		goto bus_unregister;
 	}
 
 	sdhci_msm_init_pwr_irq_wait(msm_host);
@@ -2084,7 +2309,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 					dev_name(&pdev->dev), host);
 	if (ret) {
 		dev_err(&pdev->dev, "Request IRQ failed (%d)\n", ret);
-		goto clk_disable;
+		goto bus_unregister;
 	}
 
 	pm_runtime_get_noresume(&pdev->dev);
@@ -2112,6 +2337,9 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
+bus_unregister:
+	sdhci_msm_bus_voting(host, false);
+	sdhci_msm_bus_unregister(&pdev->dev, msm_host);
 clk_disable:
 	clk_bulk_disable_unprepare(ARRAY_SIZE(msm_host->bulk_clks),
 				   msm_host->bulk_clks);
@@ -2141,6 +2369,9 @@ static int sdhci_msm_remove(struct platform_device *pdev)
 				   msm_host->bulk_clks);
 	if (!IS_ERR(msm_host->bus_clk))
 		clk_disable_unprepare(msm_host->bus_clk);
+
+	sdhci_msm_bus_voting(host, false);
+	sdhci_msm_bus_unregister(&pdev->dev, msm_host);
 	sdhci_pltfm_free(pdev);
 	return 0;
 }
@@ -2153,7 +2384,7 @@ static __maybe_unused int sdhci_msm_runtime_suspend(struct device *dev)
 
 	clk_bulk_disable_unprepare(ARRAY_SIZE(msm_host->bulk_clks),
 				   msm_host->bulk_clks);
-
+	sdhci_msm_bus_voting(host, false);
 	return 0;
 }
 
@@ -2175,6 +2406,7 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
 	if (msm_host->restore_dll_config && msm_host->clk_rate)
 		return sdhci_msm_restore_sdr_dll_config(host);
 
+	sdhci_msm_bus_voting(host, true);
 	return 0;
 }
 
-- 
1.9.1

[RFC v6 2/2] dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings

[Pradeep P V K]

Add interconnect bandwidth scaling supported strings for qcom-sdhci
controller.

Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

RFC v5 -> v6:
- No changes.

 Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 5445931..9eafc41 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -46,6 +46,21 @@ Required properties:
 	"cal"	- reference clock for RCLK delay calibration (optional)
 	"sleep"	- sleep clock for RCLK delay calibration (optional)
 
+Optional Properties:
+* Following bus parameters are required for interconnect bandwidth scaling:
+- interconnects: Pairs of phandles and interconnect provider specifier
+		 to denote the edge source and destination ports of
+		 the interconnect path.
+
+- interconnect-names: For sdhc, we have two main paths.
+		1. Data path : sdhc to ddr
+		2. Config path : cpu to sdhc
+		For Data interconnect path the name supposed to be
+		is "sdhc-ddr" and for config interconnect path it is
+		"cpu-sdhc".
+		Please refer to Documentation/devicetree/bindings/
+		interconnect/ for more details.
+
 Example:
 
 	sdhc_1: sdhci@f9824900 {
@@ -63,6 +78,9 @@ Example:
 
 		clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
 		clock-names = "core", "iface";
+		interconnects = <&qnoc MASTER_SDCC_ID &qnoc SLAVE_DDR_ID>,
+				<&qnoc MASTER_CPU_ID &qnoc SLAVE_SDCC_ID>;
+		interconnect-names = "sdhc-ddr","cpu-sdhc";
 	};
 
 	sdhc_2: sdhci@f98a4900 {
-- 
1.9.1

Re: [RFC v6 1/2] mmc: sdhci-msm: Add interconnect bus bandwidth scaling support

[Matthias Kaehlcke]

Hi Pradeep,

On Mon, Mar 23, 2020 at 07:55:01PM +0530, Pradeep P V K wrote:
> Add interconnect bandwidths for SDHC driver using OPP framework that
> is required by SDHC driver based on the clock frequency and bus width
> of the card. Otherwise, the system clocks may run at minimum clock
> speed and thus affecting the performance.
> 
> This change is based on
> [RFC] mmc: host: sdhci-msm: Use the interconnect API
> (https://lkml.org/lkml/2018/10/11/499) and
> 
> [PATCH v6] Introduce Bandwidth OPPs for interconnects
> (https://lkml.org/lkml/2019/12/6/740)
> 
> Co-developed-by: Sahitya Tummala <stummala@codeaurora.org>
> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
> Co-developed-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Co-developed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> Co-developed-by: Pradeep P V K <ppvk@codeaurora.org>
> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
> ---
> 
> RFC v5 -> v6:
> - Added new goto jump tag to put both icc paths.
> - Removed bus vote data error check and added is_null check.
> - Addressed minor code style comments.
> 
>  drivers/mmc/host/sdhci-msm.c | 240 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 236 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 09ff731..469db65 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
>
> ...
>
> +/*
> + * Helper function to parse the exact OPP node
> + * Returns OPP pointer on success else NULL on error
> + */
> +static struct dev_pm_opp
> +		*sdhci_msm_find_opp_for_freq(struct sdhci_msm_host *msm_host,
> +							unsigned long bw)
> +{
> +	struct dev_pm_opp *opp;
> +	struct sdhci_host *host = mmc_priv(msm_host->mmc);
> +	unsigned int freq = bw;
> +	struct device *dev = &msm_host->pdev->dev;
> +
> +

delete one empty line

> +	if (!freq)
> +		opp = dev_pm_opp_find_peak_bw_floor(dev, &freq);
> +	else
> +		opp = dev_pm_opp_find_peak_bw_exact(dev, freq, true);
> +
> +	/* Max bandwidth vote */
> +	if (PTR_ERR(opp) == -ERANGE && freq > sdhci_msm_get_max_clock(host))
> +		opp = dev_pm_opp_find_peak_bw_ceil(dev, &bw);
> +
> +	if (IS_ERR(opp)) {
> +		dev_err(dev, "Failed to find OPP for freq:%u err:%ld\n",
> +				freq, PTR_ERR(opp));
> +		return NULL;
> +	}
> +	return opp;
> +}
>
> ...
>
> +/*
> + * Helper function to register for OPP and interconnect
> + * frameworks.
> + */
> +static struct sdhci_msm_bus_vote_data
> +		*sdhci_msm_bus_register(struct sdhci_msm_host *host,
> +				struct platform_device *pdev)
> +{
> +	struct sdhci_msm_bus_vote_data *vote_data;
> +	struct device *dev = &pdev->dev;
> +	int i, err;
> +	struct icc_path *icc_paths[BUS_INTERCONNECT_PATHS];
> +	const char *path_names[] = {
> +		"sdhc-ddr",
> +		"cpu-sdhc",
> +	};
> +
> +	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++)
> +		icc_paths[i] = of_icc_get(&pdev->dev, path_names[i]);
> +
> +	if (!icc_paths[0] && !icc_paths[1]) {
> +		dev_info(&pdev->dev, "ICC DT property is missing.Skip vote!!\n");
> +		return NULL;
> +	}
> +
> +	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++) {
> +		if (!icc_paths[i]) {
> +			dev_err(&pdev->dev, "interconnect path '%s' is not configured\n",
> +					path_names[i]);
> +			err = -EINVAL;
> +			goto handle_err;
> +		}
> +		if (IS_ERR(icc_paths[i])) {
> +			err = PTR_ERR(icc_paths[i]);
> +
> +			if (err != -EPROBE_DEFER)
> +				dev_err(&pdev->dev, "interconnect path '%s' is invalid:%d\n",
> +					path_names[i], err);
> +			goto handle_err;
> +		}
> +	}
> +
> +	err = dev_pm_opp_of_add_table(dev);
> +	if (err) {
> +		if (err == -ENODEV || err == -ENODATA)
> +			dev_err(dev, "OPP dt properties missing:%d\n", err);
> +		else
> +			dev_err(dev, "OPP registration failed:%d\n", err);
> +		goto put_icc;
> +	}
> +
> +	vote_data = devm_kzalloc(dev, sizeof(*vote_data), GFP_KERNEL);
> +	if (!vote_data) {
> +		err = -ENOMEM;
> +		goto put_icc;
> +	}
> +	vote_data->sdhc_to_ddr = icc_paths[0];
> +	vote_data->cpu_to_sdhc = icc_paths[1];
> +	return vote_data;
> +
> +handle_err:
> +	if (err) {

the check for 'err' is not needed, this code is only executed when an error
is encountered.

> +		int other = (i == 0) ? 1 : 0;
> +
> +		if (!IS_ERR_OR_NULL(icc_paths[other]))
> +			icc_put(icc_paths[other]);
> +	}
> +	return ERR_PTR(err);
> +
> +put_icc:
> +	if (err) {
> +		for (i = 0; i < BUS_INTERCONNECT_PATHS; i++)
> +			icc_put(icc_paths[i]);
> +	}
> +	return ERR_PTR(err);

The two error paths are somewhat redundant and the 'handle_err' isn't super
clear, especially since it is disconnected from the code where the error is
found.

You could have a single handler instead:

put_icc:
	for (i = 0; i < BUS_INTERCONNECT_PATHS; i++) {
		if (!IS_ERR_OR_NULL(icc_paths[i]))
			icc_put(icc_paths[i]);
        }

	return ERR_PTR(err);

Re: [RFC v6 0/2] Add SDHC interconnect bandwidth scaling

[Rajendra Nayak]

Adding Viresh and Saravana,

On 3/23/2020 7:55 PM, Pradeep P V K wrote:
> Add interconnect bandwidths for SDHC driver using OPP framework that
> is required by SDHC driver based on the clock frequency and bus width
> of the card. Otherwise, the system clocks may run at minimum clock
> speed and thus affecting the performance.
> 
> This change is based on
> [RFC] mmc: host: sdhci-msm: Use the interconnect API
> (https://lkml.org/lkml/2018/10/11/499) and
> 
> [PATCH v6] Introduce Bandwidth OPPs for interconnects
> (https://lkml.org/lkml/2019/12/6/740)

Pradeep, since your series seems to depend on the above proposed bw bindings,
can you post the DT changes for the platform that you are testing these
patches on?

Please note that the above series is currently deadlocked [1][2] with no clear path
forward for now, so looking at how you plan to use this might throw some light onto
the requirements

[1] https://lkml.org/lkml/2020/1/14/511
[2] https://lkml.org/lkml/2020/3/20/106

> 
> Pradeep P V K (2):
>    mmc: sdhci-msm: Add interconnect bus bandwidth scaling support
>    dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings
> 
>   .../devicetree/bindings/mmc/sdhci-msm.txt          |  18 ++
>   drivers/mmc/host/sdhci-msm.c                       | 240 ++++++++++++++++++++-
>   2 files changed, 254 insertions(+), 4 deletions(-)
> 

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

Re: [RFC v6 0/2] Add SDHC interconnect bandwidth scaling

[Saravana Kannan]

On Thu, Mar 26, 2020 at 2:22 AM Rajendra Nayak <rnayak@codeaurora.org> wrote:
>
> Adding Viresh and Saravana,
>
> On 3/23/2020 7:55 PM, Pradeep P V K wrote:
> > Add interconnect bandwidths for SDHC driver using OPP framework that
> > is required by SDHC driver based on the clock frequency and bus width
> > of the card. Otherwise, the system clocks may run at minimum clock
> > speed and thus affecting the performance.
> >
> > This change is based on
> > [RFC] mmc: host: sdhci-msm: Use the interconnect API
> > (https://lkml.org/lkml/2018/10/11/499) and
> >
> > [PATCH v6] Introduce Bandwidth OPPs for interconnects
> > (https://lkml.org/lkml/2019/12/6/740)
>
> Pradeep, since your series seems to depend on the above proposed bw bindings,
> can you post the DT changes for the platform that you are testing these
> patches on?
>
> Please note that the above series is currently deadlocked [1][2] with no clear path
> forward for now, so looking at how you plan to use this might throw some light onto
> the requirements
>
> [1] https://lkml.org/lkml/2020/1/14/511
> [2] https://lkml.org/lkml/2020/3/20/106

Sorry, not deadlocked. Just kinda busy. For [1] I believe I agreed
with Viresh later on. I'll respond to [2] soon.

-Saravana

>
> >
> > Pradeep P V K (2):
> >    mmc: sdhci-msm: Add interconnect bus bandwidth scaling support
> >    dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings
> >
> >   .../devicetree/bindings/mmc/sdhci-msm.txt          |  18 ++
> >   drivers/mmc/host/sdhci-msm.c                       | 240 ++++++++++++++++++++-
> >   2 files changed, 254 insertions(+), 4 deletions(-)
> >
>
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation