Messages in this thread Patch in this message | | | Date | Mon, 13 Dec 2021 11:25:55 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH v7 06/16] firmware: arm_scmi: Add configurable polling mode for transports |
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On Mon, Nov 29, 2021 at 07:11:46PM +0000, Cristian Marussi wrote: > SCMI communications along TX channels can optionally be provided of a > completion interrupt; when such interrupt is not available, command > transactions should rely on polling, where the SCMI core takes care to > repeatedly evaluate the transport-specific .poll_done() function, if > available, to determine if and when a request was fully completed or > timed out. > > Such mechanism is already present and working on a single transfer base: > SCMI protocols can indeed enable hdr.poll_completion on specific commands > ahead of each transfer and cause that transaction to be handled with > polling. > > Introduce a couple of flags to be able to enforce such polling behaviour > globally at will: > > - scmi_desc.force_polling: to statically switch the whole transport to > polling mode. > > - scmi_chan_info.no_completion_irq: to switch a single channel dynamically > to polling mode if, at runtime, is determined that no completion > interrupt was available for such channel. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > v5 --> v6 > - removed check on replies received by IRQs when xfer was requested > as poll_completion (not all transport can suppress IRQs on an xfer basis) > v4 --> v5 > - make force_polling const > - introduce polling_enabled flag to simplify checks on do_xfer > v3 --> v4: > - renamed .needs_polling flag to .no_completion_irq > - refactored error path when polling needed but not supported > --- > drivers/firmware/arm_scmi/common.h | 11 +++++++++++ > drivers/firmware/arm_scmi/driver.c | 17 +++++++++++++++++ > 2 files changed, 28 insertions(+) > > diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h > index 6438b5248c24..99b74f4d39b6 100644 > --- a/drivers/firmware/arm_scmi/common.h > +++ b/drivers/firmware/arm_scmi/common.h > @@ -339,11 +339,19 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); > * @dev: Reference to device in the SCMI hierarchy corresponding to this > * channel > * @handle: Pointer to SCMI entity handle > + * @no_completion_irq: Flag to indicate that this channel has no completion > + * interrupt mechanism for synchronous commands. > + * This can be dynamically set by transports at run-time > + * inside their provided .chan_setup(). > + * @polling_enabled: Flag used to annotate if polling mode is currently enabled > + * on this channel. > * @transport_info: Transport layer related information > */ > struct scmi_chan_info { > struct device *dev; > struct scmi_handle *handle; > + bool no_completion_irq; > + bool polling_enabled;
Do we really need a separate flag for polling_enabled ? no_completion_irq means you need to enable polling and force_polling too. Just trying to see if we can get rid of unnecessary flags.
-- Regards, Sudeep
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