netdev - Re: [PATCH net] net: qcom/emac: Fix missing clk_disable_unprepare() in error path of emac

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Date:   Fri, 7 Aug 2020 09:54:46 +0800
From:   "wanghai (M)" <wanghai38@...wei.com>
To:     Timur Tabi <timur@...nel.org>, <davem@...emloft.net>,
        <kuba@...nel.org>
CC:     <linux-kernel@...r.kernel.org>, <netdev@...r.kernel.org>
Subject: Re: [PATCH net] net: qcom/emac: Fix missing clk_disable_unprepare()
 in error path of emac_probe


在 2020/8/6 22:23, Timur Tabi 写道:
> On 8/6/20 9:06 AM, Wang Hai wrote:
>> In emac_clks_phase1_init() of emac_probe(), there may be a situation
>> in which some clk_prepare_enable() succeed and others fail.
>> If emac_clks_phase1_init() fails, goto err_undo_clocks to clean up
>> the clk that was successfully clk_prepare_enable().
>
> Good catch, however, I think the proper fix is to fix this in 
> emac_clks_phase1_init(), so that if some clocks fail, the other clocks 
> are cleaned up and then an error is returned.
>
> .
>
Thanks for your suggestion. May I fix it like this?

diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c 
b/drivers/net/ethernet/qualcomm/emac/emac.c
index 7520c02eec12..7977ad02a7c6 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac.c
@@ -474,13 +474,25 @@ static int emac_clks_phase1_init(struct 
platform_device *pdev,

         ret = clk_prepare_enable(adpt->clk[EMAC_CLK_CFG_AHB]);
         if (ret)
-               return ret;
+               goto disable_clk_axi;

         ret = clk_set_rate(adpt->clk[EMAC_CLK_HIGH_SPEED], 19200000);
         if (ret)
-               return ret;
+               goto disable_clk_cfg_ahb;

-       return clk_prepare_enable(adpt->clk[EMAC_CLK_HIGH_SPEED]);
+       ret = clk_prepare_enable(adpt->clk[EMAC_CLK_HIGH_SPEED]);
+       if (ret)
+               goto disable_clk_cfg_ahb;
+
+       return 0;
+
+disable_clk_cfg_ahb:
+       clk_disable_unprepare(adpt->clk[EMAC_CLK_CFG_AHB]);
+disable_clk_axi:
+       clk_disable_unprepare(adpt->clk[EMAC_CLK_AXI]);
+
+       return ret;
  }