Hi Bjorn,
On 05/06/2016 09:40 PM, Bjorn Andersson wrote:
The first version of the regulator support patch suffered from being
implemented in the transport driver, as a work around for resource availability
racing (EPROBE_DEFER of the core driver) with the interrupt handler.
After reconsidering the solutions discussed following that I concluded that the
interrupt management is not really part of the transport, neither conceptually
or electrically. I therefor here suggest (patch 1/3) to move the interrupt
registration and handling to the core rmi driver.
My concern with moving interrupt processing to the core is that not all
transports report attn to the rmi core using an irq. The HID and SMBus
transports which are currently in development, reside a little higher in
the stack and attention is reported using different mechanisms. We moved
interrupt handling to the transport drivers so that they could handle
the differences in how attn is reported.
This message has some of the previous discussion regarding interrupt
processing:
https://lkml.org/lkml/2015/11/28/123
Similarly, not all transports will need support for regulators.
Implementing both in the transport drivers avoids the EPROBE_DEFER
racing and avoids adding checks in the core to see if it needs to handle
interrupts and manage regulators.
Thanks,
Andrew
This solves the potential race of interrupts being delivered in the transport
driver before the core driver have been given a chance to recover from probe
deferral.
Patch 2/3 then add the necessary code for acquiring regulator handles and
enabling these.
Patch 3/3 removes the set_page() done in the transport drivers, as we can't
rely on the chip becoming available at any time during the initialization/probe
phase.
Bjorn Andersson (3):
input: rmi4: Move IRQ handling to rmi_driver
input: rmi4: Acquire and enable VDD and VIO supplies
input: rmi4: Remove set_page() call before core is initialized
.../devicetree/bindings/input/rmi4/rmi_i2c.txt | 6 ++
.../devicetree/bindings/input/rmi4/rmi_spi.txt | 6 ++
drivers/input/rmi4/rmi_driver.c | 89 +++++++++++++++++++++-
drivers/input/rmi4/rmi_i2c.c | 84 ++------------------
drivers/input/rmi4/rmi_spi.c | 83 ++------------------
include/linux/rmi.h | 11 ++-
6 files changed, 118 insertions(+), 161 deletions(-)
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