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

From: wanghai (M)
Date: Thu Aug 06 2020 - 21:54:56 EST



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;
 }