Re: [PATCH 3/3] clk: Drop the rate range on clk_put

[kernel test robot <lkp@intel.com>]

Hi Maxime,

I love your patch! Perhaps something to improve:

[auto build test WARNING on clk/clk-next]
[also build test WARNING on next-20220325]
[cannot apply to v5.17]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Maxime-Ripard/clk-Some-Clock-Range-Fixes/20220325-190055
base:   https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-next
config: arm-oxnas_v6_defconfig (https://download.01.org/0day-ci/archive/20220325/202203252333.iuCaJrqe-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/b7aab8e3d4794c4df1a43452696f95b4eee510f5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Maxime-Ripard/clk-Some-Clock-Range-Fixes/20220325-190055
        git checkout b7aab8e3d4794c4df1a43452696f95b4eee510f5
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arm SHELL=/bin/bash drivers/clk/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/clk/clk.c:2346: warning: expecting prototype for clk_set_rate_range(). Prototype was for clk_set_rate_range_nolock() instead


vim +2346 drivers/clk/clk.c

55e9b8b7b806ec Jerome Brunet 2017-12-01  2334  
4dff95dc9477a3 Stephen Boyd  2015-04-30  2335  /**
4dff95dc9477a3 Stephen Boyd  2015-04-30  2336   * clk_set_rate_range - set a rate range for a clock source
4dff95dc9477a3 Stephen Boyd  2015-04-30  2337   * @clk: clock source
4dff95dc9477a3 Stephen Boyd  2015-04-30  2338   * @min: desired minimum clock rate in Hz, inclusive
4dff95dc9477a3 Stephen Boyd  2015-04-30  2339   * @max: desired maximum clock rate in Hz, inclusive
4dff95dc9477a3 Stephen Boyd  2015-04-30  2340   *
4dff95dc9477a3 Stephen Boyd  2015-04-30  2341   * Returns success (0) or negative errno.
4dff95dc9477a3 Stephen Boyd  2015-04-30  2342   */
b7aab8e3d4794c Maxime Ripard 2022-03-25  2343  static int clk_set_rate_range_nolock(struct clk *clk,
b7aab8e3d4794c Maxime Ripard 2022-03-25  2344  				     unsigned long min,
b7aab8e3d4794c Maxime Ripard 2022-03-25  2345  				     unsigned long max)
a093bde2b45a0a Ulf Hansson   2012-08-31 @2346  {
4dff95dc9477a3 Stephen Boyd  2015-04-30  2347  	int ret = 0;
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2348  	unsigned long old_min, old_max, rate;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2349  
b7aab8e3d4794c Maxime Ripard 2022-03-25  2350  	lockdep_assert_held(&prepare_lock);
b7aab8e3d4794c Maxime Ripard 2022-03-25  2351  
4dff95dc9477a3 Stephen Boyd  2015-04-30  2352  	if (!clk)
4dff95dc9477a3 Stephen Boyd  2015-04-30  2353  		return 0;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2354  
03813d9b7d4368 Maxime Ripard 2020-12-07  2355  	trace_clk_set_rate_range(clk->core, min, max);
03813d9b7d4368 Maxime Ripard 2020-12-07  2356  
4dff95dc9477a3 Stephen Boyd  2015-04-30  2357  	if (min > max) {
4dff95dc9477a3 Stephen Boyd  2015-04-30  2358  		pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
4dff95dc9477a3 Stephen Boyd  2015-04-30  2359  		       __func__, clk->core->name, clk->dev_id, clk->con_id,
4dff95dc9477a3 Stephen Boyd  2015-04-30  2360  		       min, max);
4dff95dc9477a3 Stephen Boyd  2015-04-30  2361  		return -EINVAL;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2362  	}
a093bde2b45a0a Ulf Hansson   2012-08-31  2363  
55e9b8b7b806ec Jerome Brunet 2017-12-01  2364  	if (clk->exclusive_count)
55e9b8b7b806ec Jerome Brunet 2017-12-01  2365  		clk_core_rate_unprotect(clk->core);
55e9b8b7b806ec Jerome Brunet 2017-12-01  2366  
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2367  	/* Save the current values in case we need to rollback the change */
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2368  	old_min = clk->min_rate;
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2369  	old_max = clk->max_rate;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2370  	clk->min_rate = min;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2371  	clk->max_rate = max;
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2372  
10c46f2ea91420 Maxime Ripard 2022-02-25  2373  	if (!clk_core_check_boundaries(clk->core, min, max)) {
10c46f2ea91420 Maxime Ripard 2022-02-25  2374  		ret = -EINVAL;
10c46f2ea91420 Maxime Ripard 2022-02-25  2375  		goto out;
10c46f2ea91420 Maxime Ripard 2022-02-25  2376  	}
10c46f2ea91420 Maxime Ripard 2022-02-25  2377  
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2378  	/*
c80ac50cbb378a Maxime Ripard 2022-02-25  2379  	 * Since the boundaries have been changed, let's give the
c80ac50cbb378a Maxime Ripard 2022-02-25  2380  	 * opportunity to the provider to adjust the clock rate based on
c80ac50cbb378a Maxime Ripard 2022-02-25  2381  	 * the new boundaries.
c80ac50cbb378a Maxime Ripard 2022-02-25  2382  	 *
c80ac50cbb378a Maxime Ripard 2022-02-25  2383  	 * We also need to handle the case where the clock is currently
c80ac50cbb378a Maxime Ripard 2022-02-25  2384  	 * outside of the boundaries. Clamping the last requested rate
c80ac50cbb378a Maxime Ripard 2022-02-25  2385  	 * to the current minimum and maximum will also handle this.
c80ac50cbb378a Maxime Ripard 2022-02-25  2386  	 *
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2387  	 * FIXME:
c80ac50cbb378a Maxime Ripard 2022-02-25  2388  	 * There is a catch. It may fail for the usual reason (clock
c80ac50cbb378a Maxime Ripard 2022-02-25  2389  	 * broken, clock protected, etc) but also because:
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2390  	 * - round_rate() was not favorable and fell on the wrong
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2391  	 *   side of the boundary
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2392  	 * - the determine_rate() callback does not really check for
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2393  	 *   this corner case when determining the rate
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2394  	 */
a9b269310ad9ab Maxime Ripard 2022-02-25  2395  	rate = clamp(clk->core->req_rate, min, max);
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2396  	ret = clk_core_set_rate_nolock(clk->core, rate);
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2397  	if (ret) {
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2398  		/* rollback the changes */
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2399  		clk->min_rate = old_min;
6562fbcf3ad5ff Jerome Brunet 2017-12-01  2400  		clk->max_rate = old_max;
4dff95dc9477a3 Stephen Boyd  2015-04-30  2401  	}
a093bde2b45a0a Ulf Hansson   2012-08-31  2402  
10c46f2ea91420 Maxime Ripard 2022-02-25  2403  out:
55e9b8b7b806ec Jerome Brunet 2017-12-01  2404  	if (clk->exclusive_count)
55e9b8b7b806ec Jerome Brunet 2017-12-01  2405  		clk_core_rate_protect(clk->core);
a093bde2b45a0a Ulf Hansson   2012-08-31  2406  
b7aab8e3d4794c Maxime Ripard 2022-03-25  2407  	return ret;
b7aab8e3d4794c Maxime Ripard 2022-03-25  2408  }
b7aab8e3d4794c Maxime Ripard 2022-03-25  2409  

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