Re: [PATCH v3 4/6] uio: Add X-Gene QMTM UIO driver

[Varka Bhadram <varkabhadram@gmail.com>]

On 10/21/2014 11:46 AM, Ankit Jindal wrote:
> On 21 October 2014 11:34, Varka Bhadram <varkabhadram@gmail.com> wrote:
>> On 10/21/2014 11:26 AM, Ankit Jindal wrote:
>>> The Applied Micro X-Gene SOC has on-chip QMTM (Queue manager
>>> and Traffic manager) which is hardware based Queue or Ring
>>> manager. This QMTM device can be used in conjunction with
>>> other devices such as DMA Engine, Ethernet, Security Engine,
>>> etc to assign work based on queues or rings.
>>>
>>> This patch allows user space access to X-Gene QMTM device.
>>>
>>> Signed-off-by: Ankit Jindal <ankit.jindal@linaro.org>
>>> Signed-off-by: Tushar Jagad <tushar.jagad@linaro.org>
>>
>> (...)
>>
>>
>>> +
>>> +static int qmtm_probe(struct platform_device *pdev)
>>> +{
>>> +       struct uio_info *info;
>>> +       struct uio_qmtm_dev *qmtm_dev;
>>> +       struct resource *csr;
>>> +       struct resource *fabric;
>>> +       struct resource qpool;
>>> +       unsigned int num_queues;
>>> +       unsigned int devid;
>>> +       phandle qpool_phandle;
>>> +       struct device_node *qpool_node;
>>> +       int ret;
>>> +
>>> +       qmtm_dev = devm_kzalloc(&pdev->dev, sizeof(struct uio_qmtm_dev),
>>> +                               GFP_KERNEL);
>>> +       if (!qmtm_dev)
>>> +               return -ENOMEM;
>>> +
>>> +       qmtm_dev->info = devm_kzalloc(&pdev->dev, sizeof(*info),
>>> GFP_KERNEL);
>>> +       if (!qmtm_dev->info)
>>> +               return -ENOMEM;
>>> +
>>> +       /* Power on qmtm in case its not done as part of boot-loader */
>>> +       qmtm_dev->qmtm_clk = devm_clk_get(&pdev->dev, NULL);
>>> +       if (IS_ERR(qmtm_dev->qmtm_clk)) {
>>> +               dev_err(&pdev->dev, "Failed to get clock\n");
>>> +               ret = PTR_ERR(qmtm_dev->qmtm_clk);
>>> +               return ret;
>>> +       }
>>> +
>>> +       csr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +       if (!csr) {
>>> +               ret = -ENODEV;
>>> +               dev_err(&pdev->dev, "No QMTM CSR resource specified\n");
>>> +               goto out_err;
>>> +       }
>>> +
>>
>> This error check is not required. *csr* is checked in
>> devm_ioremap_resource().
> I think its better to do sanity check before calling any function.

It will be the duplication of code for sanity check. This sanity check is happening
with devm_ioremap_resource(). No need to check it explicitly.

>>> +       if (!csr->start) {
>>> +               ret = -EINVAL;
>>> +               dev_err(&pdev->dev, "Invalid CSR resource\n");
>>> +               goto out_err;
>>> +       }
>>> +
>>> +       fabric = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>> +       if (!fabric) {
>>> +               ret = -ENODEV;
>>> +               dev_err(&pdev->dev, "No QMTM Fabric resource
>>> specified\n");
>>> +               goto out_err;
>>> +       }
>>> +
>>
>> same
> We do not ioremap this address.

Ok..

-- 
Regards,
Varka Bhadram.