From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: [PATCH] clk: tegra: dfll: Fix drvdata overwriting issue Date: Thu, 12 Oct 2017 16:09:59 -0700 Message-ID: <1507849799-4256-1-git-send-email-nicoleotsuka@gmail.com> Return-path: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: pdeschrijver-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org List-Id: linux-tegra@vger.kernel.org Both tegra124-dfll and clk-dfll are using platform_set_drvdata to set drvdata of the exact same pdev while they use different pointers for the drvdata. Once the drvdata has been overwritten by tegra124-dfll, clk-dfll will never get its td pointer as it expects. Since tegra124-dfll merely needs its soc pointer in its remove function, this patch fixes the bug by removing the overwriting in the tegra124-dfll file and letting the tegra_dfll_unregister return an soc pointer for it. Signed-off-by: Nicolin Chen --- As I don't have a T124 platform, I can't verify it on a board. If someone could provide a Tested-by, it would be very helpful. The test could be a simple system suspend/resume that activates runtime_suspend/resume() where a platform_get_drvdata() would be called. -- Nicolin drivers/clk/tegra/clk-dfll.c | 10 +++++----- drivers/clk/tegra/clk-dfll.h | 2 +- drivers/clk/tegra/clk-tegra124-dfll-fcpu.c | 12 +++++------- 3 files changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c index 2c44aeb..0a7deee 100644 --- a/drivers/clk/tegra/clk-dfll.c +++ b/drivers/clk/tegra/clk-dfll.c @@ -1728,10 +1728,10 @@ EXPORT_SYMBOL(tegra_dfll_register); * @pdev: DFLL platform_device * * * Unbind this driver from the DFLL hardware device represented by - * @pdev. The DFLL must be disabled for this to succeed. Returns 0 - * upon success or -EBUSY if the DFLL is still active. + * @pdev. The DFLL must be disabled for this to succeed. Returns a + * soc pointer upon success or -EBUSY if the DFLL is still active. */ -int tegra_dfll_unregister(struct platform_device *pdev) +struct tegra_dfll_soc_data *tegra_dfll_unregister(struct platform_device *pdev) { struct tegra_dfll *td = platform_get_drvdata(pdev); @@ -1739,7 +1739,7 @@ int tegra_dfll_unregister(struct platform_device *pdev) if (td->mode != DFLL_DISABLED) { dev_err(&pdev->dev, "must disable DFLL before removing driver\n"); - return -EBUSY; + return ERR_PTR(-EBUSY); } debugfs_remove_recursive(td->debugfs_dir); @@ -1753,6 +1753,6 @@ int tegra_dfll_unregister(struct platform_device *pdev) reset_control_assert(td->dvco_rst); - return 0; + return td->soc; } EXPORT_SYMBOL(tegra_dfll_unregister); diff --git a/drivers/clk/tegra/clk-dfll.h b/drivers/clk/tegra/clk-dfll.h index ed2ad88..83352c8 100644 --- a/drivers/clk/tegra/clk-dfll.h +++ b/drivers/clk/tegra/clk-dfll.h @@ -43,7 +43,7 @@ struct tegra_dfll_soc_data { int tegra_dfll_register(struct platform_device *pdev, struct tegra_dfll_soc_data *soc); -int tegra_dfll_unregister(struct platform_device *pdev); +struct tegra_dfll_soc_data *tegra_dfll_unregister(struct platform_device *pdev); int tegra_dfll_runtime_suspend(struct device *dev); int tegra_dfll_runtime_resume(struct device *dev); diff --git a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c index ad1c1cc..269d359 100644 --- a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c +++ b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c @@ -125,19 +125,17 @@ static int tegra124_dfll_fcpu_probe(struct platform_device *pdev) return err; } - platform_set_drvdata(pdev, soc); - return 0; } static int tegra124_dfll_fcpu_remove(struct platform_device *pdev) { - struct tegra_dfll_soc_data *soc = platform_get_drvdata(pdev); - int err; + struct tegra_dfll_soc_data *soc; - err = tegra_dfll_unregister(pdev); - if (err < 0) - dev_err(&pdev->dev, "failed to unregister DFLL: %d\n", err); + soc = tegra_dfll_unregister(pdev); + if (IS_ERR(soc)) + dev_err(&pdev->dev, "failed to unregister DFLL: %ld\n", + PTR_ERR(soc)); tegra_cvb_remove_opp_table(soc->dev, soc->cvb, soc->max_freq); -- 2.1.4