linux-kernel - Re: [PATCH 1/2] staging: fsl-mc: Allocate IRQ's before scanning DPRC objects

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Date:   Wed, 6 Dec 2017 13:30:17 +0000
From:   Laurentiu Tudor <laurentiu.tudor@....com>
To:     Nipun Gupta <nipun.gupta@....com>,
        "stuyoder@...il.com" <stuyoder@...il.com>,
        Bharat Bhushan <bharat.bhushan@....com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "cakturk@...il.com" <cakturk@...il.com>,
        "bretth256@...il.com" <bretth256@...il.com>,
        "arnd@...db.de" <arnd@...db.de>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "devel@...verdev.osuosl.org" <devel@...verdev.osuosl.org>
Subject: Re: [PATCH 1/2] staging: fsl-mc: Allocate IRQ's before scanning DPRC
 objects

Hi Nipun,

Can you polish a bit this commit message? It doesn't seem to explain why 
this is needed.

On 12/06/2017 06:18 PM, Nipun Gupta wrote:
> When DPRC probing is deferred (such as where IOMMU is not probed
> before the fsl-mc bus), all the devices in the DPRC containers gets
> initialized one after another.

Are you referring to dprc probing being deferred (do we ever do that?) 
or devices inside the dprc deferring the probe?

> As IRQ's were allocated only once the
> DPRC scanning is completed, the devices like DPIO which uses these
> IRQ's at initalization fails. This patch allocates the IRQ resources

s/initalization/initialization

> before scanning all the objects in the DPRC container.
>
> Signed-off-by: Nipun Gupta <nipun.gupta@....com>
> ---
>   drivers/staging/fsl-mc/bus/dprc-driver.c | 49 ++++++++++++++++++--------------
>   1 file changed, 27 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/staging/fsl-mc/bus/dprc-driver.c b/drivers/staging/fsl-mc/bus/dprc-driver.c
> index 06df528..7265431 100644
> --- a/drivers/staging/fsl-mc/bus/dprc-driver.c
> +++ b/drivers/staging/fsl-mc/bus/dprc-driver.c
> @@ -206,7 +206,8 @@ static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
>    * dprc_scan_objects - Discover objects in a DPRC
>    *
>    * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
> - * @total_irq_count: total number of IRQs needed by objects in the DPRC.
> + * @total_irq_count: If argument is provided the function populates the
> + * total number of IRQs created by objects in the DPRC.

As a side node, after a cursory look i noticed that this total_irq_count 
parameter is used only for some sanity checks. I'm thinking of dropping 
it in a follow-up cleanup patch.

---
Best Regards, Laurentiu