netdev - Re: [RFC PATCH 09/12] soc: qcom: ipa: main IPA source file

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Date:   Wed, 7 Nov 2018 15:08:46 +0100
From:   Arnd Bergmann <arnd@...db.de>
To:     Alex Elder <elder@...aro.org>
Cc:     David Miller <davem@...emloft.net>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Ilias Apalodimas <ilias.apalodimas@...aro.org>,
        Networking <netdev@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>, linux-arm-msm@...r.kernel.org,
        linux-soc@...r.kernel.org,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        syadagir@...eaurora.org, mjavid@...eaurora.org,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>
Subject: Re: [RFC PATCH 09/12] soc: qcom: ipa: main IPA source file

On Wed, Nov 7, 2018 at 1:33 AM Alex Elder <elder@...aro.org> wrote:

> +static void ipa_client_remove_deferred(struct work_struct *work);

Try to avoid forward declarations by reordering the code in call order,
it will also make it easier to read.

> +static DECLARE_WORK(ipa_client_remove_work, ipa_client_remove_deferred);
> +
> +static struct ipa_context ipa_ctx_struct;
> +struct ipa_context *ipa_ctx = &ipa_ctx_struct;

Global state variables should generally be removed as well, and
passed around as function arguments.

> +static int hdr_init_local_cmd(u32 offset, u32 size)
> +{
> +       struct ipa_desc desc = { };
> +       struct ipa_dma_mem mem;
> +       void *payload;
> +       int ret;
> +
> +       if (ipa_dma_alloc(&mem, size, GFP_KERNEL))
> +               return -ENOMEM;
> +
> +       offset += ipa_ctx->smem_offset;
> +
> +       payload = ipahal_hdr_init_local_pyld(&mem, offset);
> +       if (!payload) {
> +               ret = -ENOMEM;
> +               goto err_dma_free;
> +       }
> +
> +       desc.type = IPA_IMM_CMD_DESC;
> +       desc.len_opcode = IPA_IMM_CMD_HDR_INIT_LOCAL;
> +       desc.payload = payload;
> +
> +       ret = ipa_send_cmd(&desc);

You have a bunch of dynamic allocations in here, which you
then immediately tear down again after the command is complete.
I can't see at all what you do with the DMA address, since you
seem to not use the virtual address at all but only store
the physical address in some kind of descriptor without ever
writing to it.

Am I missing something here?

> +/* Remoteproc callbacks for SSR events: prepare, start, stop, unprepare */
> +int ipa_ssr_prepare(struct rproc_subdev *subdev)
> +{
> +       printk("======== SSR prepare received ========\n");

I think you mean dev_dbg() here. A plain printk() without a level
is not correct and we probably don't want those messages to arrive
on the console for normal users.

> +static int ipa_firmware_load(struct de
> +
> +err_clear_dev:
> +       ipa_ctx->lan_cons_ep_id = 0;
> +       ipa_ctx->cmd_prod_ep_id = 0;
> +       ipahal_exit();
> +err_dma_exit:
> +       ipa_dma_exit();
> +err_clear_gsi:
> +       ipa_ctx->gsi = NULL;
> +       ipa_ctx->ipa_phys = 0;
> +       ipa_reg_exit();
> +err_clear_ipa_irq:
> +       ipa_ctx->ipa_irq = 0;
> +err_clear_filter_bitmap:
> +       ipa_ctx->filter_bitmap = 0;
> +err_interconnect_exit:
> +       ipa_interconnect_exit();
> +err_clock_exit:
> +       ipa_clock_exit();
> +       ipa_ctx->dev = NULL;
> +out_smp2p_exit:
> +       ipa_smp2p_exit(dev);
> +

No need to initialize members to zero when you are about
to free the structure.

> +static struct platform_driver ipa_plat_drv = {
> +       .probe = ipa_plat_drv_probe,
> +       .remove = ipa_plat_drv_remove,
> +       .driver = {
> +               .name = "ipa",
> +               .owner = THIS_MODULE,
> +               .pm = &ipa_pm_ops,
> +               .of_match_table = ipa_plat_drv_match,
> +       },
> +};
> +
> +builtin_platform_driver(ipa_plat_drv);

This should be module_platform_driver(), and allow unloading
the driver.

        Arnd