Messages in this thread | | | Subject | Re: [PATCH v3 3/8] mailbox: Add transmit done by blocking option | From | Mikko Perttunen <> | Date | Wed, 8 Aug 2018 14:38:28 +0300 |
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On 04.08.2018 13:45, Mikko Perttunen wrote: > On 08/03/2018 03:54 PM, Jassi Brar wrote: >> On Mon, Jul 2, 2018 at 5:10 PM, Mikko Perttunen >> <mperttunen@nvidia.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.
I tried using polling in the mailbox framework. Some printing is done from atomic context so it seems tx_block cannot be used - wait_for_completion_timeout understandably does not work in atomic context. I also tried without tx_block, in which case I got some horribly garbled output, but "Try increasing MBOX_TX_QUEUE_LEN" was readable there.
Any opinions?
Thanks, Mikko
> >> >> 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@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-tegra" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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