linux-kernel - Re: [PATCH v3 3/8] mailbox: Add transmit done by blocking option

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <907bac36-0c54-8f38-0f5e-f59196d414c6@kapsi.fi>
Date:   Sat, 4 Aug 2018 13:45:49 +0300
From:   Mikko Perttunen <cyndis@...si.fi>
To:     Jassi Brar <jassisinghbrar@...il.com>,
        Mikko Perttunen <mperttunen@...dia.com>
Cc:     Greg KH <gregkh@...uxfoundation.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Jon Hunter <jonathanh@...dia.com>,
        Devicetree List <devicetree@...r.kernel.org>,
        linux-serial@...r.kernel.org, linux-tegra@...r.kernel.org,
        ", linux-arm-kernel"@lists.infradead.org,
        linux-mediatek@...ts.infradead.org,
        srv_heupstream <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 3/8] mailbox: Add transmit done by blocking option

On 08/03/2018 03:54 PM, Jassi Brar wrote:
> On Mon, Jul 2, 2018 at 5:10 PM, Mikko Perttunen <mperttunen@...dia.com> wrote:
>> Add a new TXDONE option, TXDONE_BY_BLOCK. With this option, the
>> send_data function of the mailbox driver is expected to block until
>> the message has been sent. The new option is used with the Tegra
>> Combined UART driver to minimize unnecessary overhead when transmitting
>> data.
>>
> 1) TXDONE_BY_BLOCK flag :-
>          Have you tried setting the flag mbox_chan->mbox_client->tx_block ?

No - I suppose I should have done that. I'm a bit concerned about 
overhead as send_data may be called thousands of times per second, so I 
tried to make it as close as possible to the downstream driver that just 
pokes the mailbox register directly.

> 
> 2) Implementing TEGRA_HSP_MBOX_TYPE_SM :-
>         In mailbox framework, a controller is a collection of identical
> channels. That is, instances of the same class.
>         So ideally, in probe you should populate a controller for each
> type of channel, i.e, DB, SM, SS and AS.

Hmm, yes, I guess this would be possible if I change the mailbox core to 
allow registering multiple controllers per device.

Thanks!
Mikko

> --
> To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>