Re: [PATCH] arch: arm: mach-omap2: omap-pm-noop.c: Remove some unused functions

From: Nishanth Menon
Date: Sun Dec 07 2014 - 16:16:04 EST


On 12/07/2014 02:49 PM, Rickard Strandqvist wrote:
Removes some functions that are not used anywhere:
omap_pm_set_max_dev_wakeup_lat() omap_pm_if_exit() omap_pm_cpu_get_freq()
omap_pm_cpu_set_freq() omap_pm_cpu_get_freq_table() omap_pm_dsp_get_opp()
omap_pm_dsp_set_min_opp() omap_pm_dsp_get_opp_table()
omap_pm_set_min_clk_rate() omap_pm_set_max_sdma_lat()

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/omap-pm-noop.c | 196 ------------------------------------
arch/arm/mach-omap2/omap-pm.h | 192 -----------------------------------
2 files changed, 388 deletions(-)



That kind of opens up as to if any of the functions make sense anymore...


diff --git a/arch/arm/mach-omap2/omap-pm-noop.c b/arch/arm/mach-omap2/omap-pm-noop.c
index 6a3be2b..a1ee806 100644
--- a/arch/arm/mach-omap2/omap-pm-noop.c
+++ b/arch/arm/mach-omap2/omap-pm-noop.c
@@ -86,200 +86,10 @@ int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
return 0;
}

-int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
- long t)
-{
- if (!req_dev || !dev || t < -1) {
- WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
- return -EINVAL;
- }
-
- if (t == -1)
- pr_debug("OMAP PM: remove max device latency constraint: dev %s\n",
- dev_name(dev));
- else
- pr_debug("OMAP PM: add max device latency constraint: dev %s, t = %ld usec\n",
- dev_name(dev), t);
-
- /*
- * For current Linux, this needs to map the device to a
- * powerdomain, then go through the list of current max lat
- * constraints on that powerdomain and find the smallest. If
- * the latency constraint has changed, the code should
- * recompute the state to enter for the next powerdomain
- * state. Conceivably, this code should also determine
- * whether to actually disable the device clocks or not,
- * depending on how long it takes to re-enable the clocks.
- *
- * TI CDP code can call constraint_set here.
- */
-
- return 0;
-}
-
-int omap_pm_set_max_sdma_lat(struct device *dev, long t)
-{
- if (!dev || t < -1) {
- WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
- return -EINVAL;
- }
-
- if (t == -1)
- pr_debug("OMAP PM: remove max DMA latency constraint: dev %s\n",
- dev_name(dev));
- else
- pr_debug("OMAP PM: add max DMA latency constraint: dev %s, t = %ld usec\n",
- dev_name(dev), t);
-
- /*
- * For current Linux PM QOS params, this code should scan the
- * list of maximum CPU and DMA latencies and select the
- * smallest, then set cpu_dma_latency pm_qos_param
- * accordingly.
- *
- * For future Linux PM QOS params, with separate CPU and DMA
- * latency params, this code should just set the dma_latency param.
- *
- * TI CDP code can call constraint_set here.
- */
-
- return 0;
-}
-
-int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
-{
- if (!dev || !c || r < 0) {
- WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
- return -EINVAL;
- }
-
- if (r == 0)
- pr_debug("OMAP PM: remove min clk rate constraint: dev %s\n",
- dev_name(dev));
- else
- pr_debug("OMAP PM: add min clk rate constraint: dev %s, rate = %ld Hz\n",
- dev_name(dev), r);
-
- /*
- * Code in a real implementation should keep track of these
- * constraints on the clock, and determine the highest minimum
- * clock rate. It should iterate over each OPP and determine
- * whether the OPP will result in a clock rate that would
- * satisfy this constraint (and any other PM constraint in effect
- * at that time). Once it finds the lowest-voltage OPP that
- * meets those conditions, it should switch to it, or return
- * an error if the code is not capable of doing so.
- */
-
- return 0;
-}
-
/*
* DSP Bridge-specific constraints
*/

-const struct omap_opp *omap_pm_dsp_get_opp_table(void)
-{
- pr_debug("OMAP PM: DSP request for OPP table\n");
-
- /*
- * Return DSP frequency table here: The final item in the
- * array should have .rate = .opp_id = 0.
- */
-
- return NULL;
-}
-
-void omap_pm_dsp_set_min_opp(u8 opp_id)
-{
- if (opp_id == 0) {
- WARN_ON(1);
- return;
- }
-
- pr_debug("OMAP PM: DSP requests minimum VDD1 OPP to be %d\n", opp_id);
-
- /*
- *
- * For l-o dev tree, our VDD1 clk is keyed on OPP ID, so we
- * can just test to see which is higher, the CPU's desired OPP
- * ID or the DSP's desired OPP ID, and use whichever is
- * highest.
- *
- * In CDP12.14+, the VDD1 OPP custom clock that controls the DSP
- * rate is keyed on MPU speed, not the OPP ID. So we need to
- * map the OPP ID to the MPU speed for use with clk_set_rate()
- * if it is higher than the current OPP clock rate.
- *
- */
-}
-
-
-u8 omap_pm_dsp_get_opp(void)
-{
- pr_debug("OMAP PM: DSP requests current DSP OPP ID\n");
-
- /*
- * For l-o dev tree, call clk_get_rate() on VDD1 OPP clock
- *
- * CDP12.14+:
- * Call clk_get_rate() on the OPP custom clock, map that to an
- * OPP ID using the tables defined in board-*.c/chip-*.c files.
- */
-
- return 0;
-}
-
-/*
- * CPUFreq-originated constraint
- *
- * In the future, this should be handled by custom OPP clocktype
- * functions.
- */
-
-struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void)
-{
- pr_debug("OMAP PM: CPUFreq request for frequency table\n");
-
- /*
- * Return CPUFreq frequency table here: loop over
- * all VDD1 clkrates, pull out the mpu_ck frequencies, build
- * table
- */
-
- return NULL;
-}
-
-void omap_pm_cpu_set_freq(unsigned long f)
-{
- if (f == 0) {
- WARN_ON(1);
- return;
- }
-
- pr_debug("OMAP PM: CPUFreq requests CPU frequency to be set to %lu\n",
- f);
-
- /*
- * For l-o dev tree, determine whether MPU freq or DSP OPP id
- * freq is higher. Find the OPP ID corresponding to the
- * higher frequency. Call clk_round_rate() and clk_set_rate()
- * on the OPP custom clock.
- *
- * CDP should just be able to set the VDD1 OPP clock rate here.
- */
-}
-
-unsigned long omap_pm_cpu_get_freq(void)
-{
- pr_debug("OMAP PM: CPUFreq requests current CPU frequency\n");
-
- /*
- * Call clk_get_rate() on the mpu_ck.
- */
-
- return 0;
-}

/**
* omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
@@ -363,9 +173,3 @@ int __init omap_pm_if_init(void)
{
return 0;
}
-
-void omap_pm_if_exit(void)
-{
- /* Deallocate CPUFreq frequency table here */
-}
-
diff --git a/arch/arm/mach-omap2/omap-pm.h b/arch/arm/mach-omap2/omap-pm.h
index 1d777e6..109bef5 100644
--- a/arch/arm/mach-omap2/omap-pm.h
+++ b/arch/arm/mach-omap2/omap-pm.h
@@ -50,14 +50,6 @@ int __init omap_pm_if_early_init(void);
*/
int __init omap_pm_if_init(void);

-/**
- * omap_pm_if_exit - OMAP PM exit code
- *
- * Exit code; currently unused. The "_if_" is to avoid name
- * collisions with the PM idle-loop code.
- */
-void omap_pm_if_exit(void);
-
/*
* Device-driver-originated constraints (via board-*.c files, platform_data)
*/
@@ -132,163 +124,6 @@ int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t);
int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r);


-/**
- * omap_pm_set_max_dev_wakeup_lat - set the maximum device enable latency
- * @req_dev: struct device * requesting the constraint, or NULL if none
- * @dev: struct device * to set the constraint one
- * @t: maximum device wakeup latency in microseconds
- *
- * Request that the maximum amount of time necessary for a device @dev
- * to become accessible after its clocks are enabled should be no
- * greater than @t microseconds. Specifically, this represents the
- * time from when a device driver enables device clocks with
- * clk_enable(), to when the register reads and writes on the device
- * will succeed. This function should be called before clk_disable()
- * is called, since the power state transition decision may be made
- * during clk_disable().
- *
- * It is intended that underlying PM code will use this information to
- * determine what power state to put the powerdomain enclosing this
- * device into.
- *
- * Multiple calls to omap_pm_set_max_dev_wakeup_lat() will replace the
- * previous wakeup latency values for this device. To remove the
- * wakeup latency restriction for this device, call with t = -1.
- *
- * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
- * is not satisfiable, or 0 upon success.
- */
-int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
- long t);
-
-
-/**
- * omap_pm_set_max_sdma_lat - set the maximum system DMA transfer start latency
- * @dev: struct device *
- * @t: maximum DMA transfer start latency in microseconds
- *
- * Request that the maximum system DMA transfer start latency for this
- * device 'dev' should be no greater than 't' microseconds. "DMA
- * transfer start latency" here is defined as the elapsed time from
- * when a device (e.g., McBSP) requests that a system DMA transfer
- * start or continue, to the time at which data starts to flow into
- * that device from the system DMA controller.
- *
- * It is intended that underlying PM code will use this information to
- * determine what power state to put the CORE powerdomain into.
- *
- * Since system DMA transfers may not involve the MPU, this function
- * will not affect MPU wakeup latency. Use set_max_cpu_lat() to do
- * so. Similarly, this function will not affect device wakeup latency
- * -- use set_max_dev_wakeup_lat() to affect that.
- *
- * Multiple calls to set_max_sdma_lat() will replace the previous t
- * value for this device. To remove the maximum DMA latency for this
- * device, call with t = -1.
- *
- * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
- * is not satisfiable, or 0 upon success.
- */
-int omap_pm_set_max_sdma_lat(struct device *dev, long t);
-
-
-/**
- * omap_pm_set_min_clk_rate - set minimum clock rate requested by @dev
- * @dev: struct device * requesting the constraint
- * @clk: struct clk * to set the minimum rate constraint on
- * @r: minimum rate in Hz
- *
- * Request that the minimum clock rate on the device @dev's clk @clk
- * be no less than @r Hz.
- *
- * It is expected that the OMAP PM code will use this information to
- * find an OPP or clock setting that will satisfy this clock rate
- * constraint, along with any other applicable system constraints on
- * the clock rate or corresponding voltage, etc.
- *
- * omap_pm_set_min_clk_rate() differs from the clock code's
- * clk_set_rate() in that it considers other constraints before taking
- * any hardware action, and may change a system OPP rather than just a
- * clock rate. clk_set_rate() is intended to be a low-level
- * interface.
- *
- * omap_pm_set_min_clk_rate() is easily open to abuse. A better API
- * would be something like "omap_pm_set_min_dev_performance()";
- * however, there is no easily-generalizable concept of performance
- * that applies to all devices. Only a device (and possibly the
- * device subsystem) has both the subsystem-specific knowledge, and
- * the hardware IP block-specific knowledge, to translate a constraint
- * on "touchscreen sampling accuracy" or "number of pixels or polygons
- * rendered per second" to a clock rate. This translation can be
- * dependent on the hardware IP block's revision, or firmware version,
- * and the driver is the only code on the system that has this
- * information and can know how to translate that into a clock rate.
- *
- * The intended use-case for this function is for userspace or other
- * kernel code to communicate a particular performance requirement to
- * a subsystem; then for the subsystem to communicate that requirement
- * to something that is meaningful to the device driver; then for the
- * device driver to convert that requirement to a clock rate, and to
- * then call omap_pm_set_min_clk_rate().
- *
- * Users of this function (such as device drivers) should not simply
- * call this function with some high clock rate to ensure "high
- * performance." Rather, the device driver should take a performance
- * constraint from its subsystem, such as "render at least X polygons
- * per second," and use some formula or table to convert that into a
- * clock rate constraint given the hardware type and hardware
- * revision. Device drivers or subsystems should not assume that they
- * know how to make a power/performance tradeoff - some device use
- * cases may tolerate a lower-fidelity device function for lower power
- * consumption; others may demand a higher-fidelity device function,
- * no matter what the power consumption.
- *
- * Multiple calls to omap_pm_set_min_clk_rate() will replace the
- * previous rate value for the device @dev. To remove the minimum clock
- * rate constraint for the device, call with r = 0.
- *
- * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
- * is not satisfiable, or 0 upon success.
- */
-int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r);
-
-/*
- * DSP Bridge-specific constraints
- */
-
-/**
- * omap_pm_dsp_get_opp_table - get OPP->DSP clock frequency table
- *
- * Intended for use by DSPBridge. Returns an array of OPP->DSP clock
- * frequency entries. The final item in the array should have .rate =
- * .opp_id = 0.
- */
-const struct omap_opp *omap_pm_dsp_get_opp_table(void);
-
-/**
- * omap_pm_dsp_set_min_opp - receive desired OPP target ID from DSP Bridge
- * @opp_id: target DSP OPP ID
- *
- * Set a minimum OPP ID for the DSP. This is intended to be called
- * only from the DSP Bridge MPU-side driver. Unfortunately, the only
- * information that code receives from the DSP/BIOS load estimator is the
- * target OPP ID; hence, this interface. No return value.
- */
-void omap_pm_dsp_set_min_opp(u8 opp_id);
-
-/**
- * omap_pm_dsp_get_opp - report the current DSP OPP ID
- *
- * Report the current OPP for the DSP. Since on OMAP3, the DSP and
- * MPU share a single voltage domain, the OPP ID returned back may
- * represent a higher DSP speed than the OPP requested via
- * omap_pm_dsp_set_min_opp().
- *
- * Returns the current VDD1 OPP ID, or 0 upon error.
- */
-u8 omap_pm_dsp_get_opp(void);
-
-
/*
* CPUFreq-originated constraint
*
@@ -296,33 +131,6 @@ u8 omap_pm_dsp_get_opp(void);
* functions.
*/

-/**
- * omap_pm_cpu_get_freq_table - return a cpufreq_frequency_table array ptr
- *
- * Provide a frequency table usable by CPUFreq for the current chip/board.
- * Returns a pointer to a struct cpufreq_frequency_table array or NULL
- * upon error.
- */
-struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void);
-
-/**
- * omap_pm_cpu_set_freq - set the current minimum MPU frequency
- * @f: MPU frequency in Hz
- *
- * Set the current minimum CPU frequency. The actual CPU frequency
- * used could end up higher if the DSP requested a higher OPP.
- * Intended to be called by plat-omap/cpu_omap.c:omap_target(). No
- * return value.
- */
-void omap_pm_cpu_set_freq(unsigned long f);
-
-/**
- * omap_pm_cpu_get_freq - report the current CPU frequency
- *
- * Returns the current MPU frequency, or 0 upon error.
- */
-unsigned long omap_pm_cpu_get_freq(void);
-

/*
* Device context loss tracking


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/