Re: [PATCHv3 08/35] clk: ti: fix ti_clk_get_reg_addr error handling

From: Tero Kristo <t-kristo@ti.com>
To: Mike Turquette <mturquette@linaro.org>,
	tony@atomide.com, paul@pwsan.com, linux-omap@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCHv3 08/35] clk: ti: fix ti_clk_get_reg_addr error handling
Date: Fri, 20 Mar 2015 09:00:46 +0200	[thread overview]
Message-ID: <550BC59E.9010408@ti.com> (raw)
In-Reply-To: <20150306191821.11109.2610@quantum>

On 03/06/2015 09:18 PM, Mike Turquette wrote:
> Quoting Tero Kristo (2015-02-25 11:04:18)
>> There is a case where NULL can be a valid return value for
>> ti_clk_get_reg_addr, specifically the case where both the provider index
>> and register offsets are zero. In this case, the current error checking
>> against a NULL pointer will fail. Thus, change the API to return a
>> ERR_PTR value in an error case, and change all the users of this API to
>> check against IS_ERR instead.
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> Cc: Michael Turquette <mturquette@linaro.org>
>
> Looks good to me.

I'll interpret this as an Acked-by, will add this tag to the latest 
version of the set I will post later today, thanks.

-Tero

>
> Regards,
> Mike
>
>> ---
>>   drivers/clk/ti/apll.c      |    5 +++--
>>   drivers/clk/ti/autoidle.c  |    2 +-
>>   drivers/clk/ti/clk.c       |    7 ++++---
>>   drivers/clk/ti/divider.c   |    4 ++--
>>   drivers/clk/ti/dpll.c      |    6 +++---
>>   drivers/clk/ti/gate.c      |    4 ++--
>>   drivers/clk/ti/interface.c |    2 +-
>>   drivers/clk/ti/mux.c       |    4 ++--
>>   8 files changed, 18 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/clk/ti/apll.c b/drivers/clk/ti/apll.c
>> index 72d9727..49baf38 100644
>> --- a/drivers/clk/ti/apll.c
>> +++ b/drivers/clk/ti/apll.c
>> @@ -203,7 +203,7 @@ static void __init of_dra7_apll_setup(struct device_node *node)
>>          ad->control_reg = ti_clk_get_reg_addr(node, 0);
>>          ad->idlest_reg = ti_clk_get_reg_addr(node, 1);
>>
>> -       if (!ad->control_reg || !ad->idlest_reg)
>> +       if (IS_ERR(ad->control_reg) || IS_ERR(ad->idlest_reg))
>>                  goto cleanup;
>>
>>          ad->idlest_mask = 0x1;
>> @@ -384,7 +384,8 @@ static void __init of_omap2_apll_setup(struct device_node *node)
>>          ad->autoidle_reg = ti_clk_get_reg_addr(node, 1);
>>          ad->idlest_reg = ti_clk_get_reg_addr(node, 2);
>>
>> -       if (!ad->control_reg || !ad->autoidle_reg || !ad->idlest_reg)
>> +       if (IS_ERR(ad->control_reg) || IS_ERR(ad->autoidle_reg) ||
>> +           IS_ERR(ad->idlest_reg))
>>                  goto cleanup;
>>
>>          clk = clk_register(NULL, &clk_hw->hw);
>> diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c
>> index 8912ff8..e75c64c 100644
>> --- a/drivers/clk/ti/autoidle.c
>> +++ b/drivers/clk/ti/autoidle.c
>> @@ -119,7 +119,7 @@ int __init of_ti_clk_autoidle_setup(struct device_node *node)
>>          clk->name = node->name;
>>          clk->reg = ti_clk_get_reg_addr(node, 0);
>>
>> -       if (!clk->reg) {
>> +       if (IS_ERR(clk->reg)) {
>>                  kfree(clk);
>>                  return -EINVAL;
>>          }
>> diff --git a/drivers/clk/ti/clk.c b/drivers/clk/ti/clk.c
>> index e22b956..0ebe5c5 100644
>> --- a/drivers/clk/ti/clk.c
>> +++ b/drivers/clk/ti/clk.c
>> @@ -103,7 +103,8 @@ int __init ti_clk_retry_init(struct device_node *node, struct clk_hw *hw,
>>    * @index: register index from the clock node
>>    *
>>    * Builds clock register address from device tree information. This
>> - * is a struct of type clk_omap_reg.
>> + * is a struct of type clk_omap_reg. Returns a pointer to the register
>> + * address, or a pointer error value in failure.
>>    */
>>   void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
>>   {
>> @@ -121,14 +122,14 @@ void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
>>
>>          if (i == CLK_MAX_MEMMAPS) {
>>                  pr_err("clk-provider not found for %s!\n", node->name);
>> -               return NULL;
>> +               return ERR_PTR(-ENOENT);
>>          }
>>
>>          reg->index = i;
>>
>>          if (of_property_read_u32_index(node, "reg", index, &val)) {
>>                  pr_err("%s must have reg[%d]!\n", node->name, index);
>> -               return NULL;
>> +               return ERR_PTR(-EINVAL);
>>          }
>>
>>          reg->offset = val;
>> diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
>> index 6211893..ff5f117 100644
>> --- a/drivers/clk/ti/divider.c
>> +++ b/drivers/clk/ti/divider.c
>> @@ -530,8 +530,8 @@ static int __init ti_clk_divider_populate(struct device_node *node,
>>          u32 val;
>>
>>          *reg = ti_clk_get_reg_addr(node, 0);
>> -       if (!*reg)
>> -               return -EINVAL;
>> +       if (IS_ERR(*reg))
>> +               return PTR_ERR(*reg);
>>
>>          if (!of_property_read_u32(node, "ti,bit-shift", &val))
>>                  *shift = val;
>> diff --git a/drivers/clk/ti/dpll.c b/drivers/clk/ti/dpll.c
>> index 81dc469..11478a5 100644
>> --- a/drivers/clk/ti/dpll.c
>> +++ b/drivers/clk/ti/dpll.c
>> @@ -390,18 +390,18 @@ static void __init of_ti_dpll_setup(struct device_node *node,
>>   #endif
>>          } else {
>>                  dd->idlest_reg = ti_clk_get_reg_addr(node, 1);
>> -               if (!dd->idlest_reg)
>> +               if (IS_ERR(dd->idlest_reg))
>>                          goto cleanup;
>>
>>                  dd->mult_div1_reg = ti_clk_get_reg_addr(node, 2);
>>          }
>>
>> -       if (!dd->control_reg || !dd->mult_div1_reg)
>> +       if (IS_ERR(dd->control_reg) || IS_ERR(dd->mult_div1_reg))
>>                  goto cleanup;
>>
>>          if (dd->autoidle_mask) {
>>                  dd->autoidle_reg = ti_clk_get_reg_addr(node, 3);
>> -               if (!dd->autoidle_reg)
>> +               if (IS_ERR(dd->autoidle_reg))
>>                          goto cleanup;
>>          }
>>
>> diff --git a/drivers/clk/ti/gate.c b/drivers/clk/ti/gate.c
>> index d493307..0c6fdfc 100644
>> --- a/drivers/clk/ti/gate.c
>> +++ b/drivers/clk/ti/gate.c
>> @@ -225,7 +225,7 @@ static void __init _of_ti_gate_clk_setup(struct device_node *node,
>>
>>          if (ops != &omap_gate_clkdm_clk_ops) {
>>                  reg = ti_clk_get_reg_addr(node, 0);
>> -               if (!reg)
>> +               if (IS_ERR(reg))
>>                          return;
>>
>>                  if (!of_property_read_u32(node, "ti,bit-shift", &val))
>> @@ -264,7 +264,7 @@ _of_ti_composite_gate_clk_setup(struct device_node *node,
>>                  return;
>>
>>          gate->enable_reg = ti_clk_get_reg_addr(node, 0);
>> -       if (!gate->enable_reg)
>> +       if (IS_ERR(gate->enable_reg))
>>                  goto cleanup;
>>
>>          of_property_read_u32(node, "ti,bit-shift", &val);
>> diff --git a/drivers/clk/ti/interface.c b/drivers/clk/ti/interface.c
>> index 265d91f..c76230d 100644
>> --- a/drivers/clk/ti/interface.c
>> +++ b/drivers/clk/ti/interface.c
>> @@ -111,7 +111,7 @@ static void __init _of_ti_interface_clk_setup(struct device_node *node,
>>          u32 val;
>>
>>          reg = ti_clk_get_reg_addr(node, 0);
>> -       if (!reg)
>> +       if (IS_ERR(reg))
>>                  return;
>>
>>          if (!of_property_read_u32(node, "ti,bit-shift", &val))
>> diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
>> index 728e253..5cdeed5 100644
>> --- a/drivers/clk/ti/mux.c
>> +++ b/drivers/clk/ti/mux.c
>> @@ -210,7 +210,7 @@ static void of_mux_clk_setup(struct device_node *node)
>>
>>          reg = ti_clk_get_reg_addr(node, 0);
>>
>> -       if (!reg)
>> +       if (IS_ERR(reg))
>>                  goto cleanup;
>>
>>          of_property_read_u32(node, "ti,bit-shift", &shift);
>> @@ -283,7 +283,7 @@ static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
>>
>>          mux->reg = ti_clk_get_reg_addr(node, 0);
>>
>> -       if (!mux->reg)
>> +       if (IS_ERR(mux->reg))
>>                  goto cleanup;
>>
>>          if (!of_property_read_u32(node, "ti,bit-shift", &val))
>> --
>> 1.7.9.5
>>