On Wed, Nov 28, 2018 at 10:54:09AM +0100, Thierry Reding wrote: > From: Thierry Reding <treding@xxxxxxxxxx> > > Hi everyone, > > this is a reworked version of Mikko's earlier proposal[0]. I've reworked > the TCU driver itself so that it relies less on global variables as well > as added a Kconfig option to allow the console support to be selected. I > also fixed a couple of issues that manifested themselves as I was moving > towards the IRQ driven mode (TCU was passing a pointer to a local > variable which was getting stored in the mailbox's ring buffer and the > data pointed at was becoming stale by the time the mailbox got around to > dequeue it). > > The biggest bulk of the changes is in the mailbox driver. This series > addresses all of Jassi's comments from back at the time. One notable > additional change is that shared mailboxes are now interrupt driven, > which removes the need for polling mode. > > Unfortunately there is still an issue because the TCU uses the mailbox > in atomic context for both TTY and console modes, so we get a sleeping- > while-atomic BUG when using mbox_client->tx_block = true in order to > rate-limit mbox_send_message(). In order to work around this, I added a > new mbox_flush() API that will allow flushing the mailbox in atomic > context by using the mailbox controller's implementation of ->flush(). > For Tegra HSP shared mailboxes this is done by spinning on the shared > mailbox register until the receiver has marked the mailbox as empty. I > have been running this locally for a couple of days now and it works > perfectly. > > Furthermore this series incorporates Mikko's work in progress on > splitting up the mailbox controllers and allowing multiple controllers > to match on the same device tree node during mbox_request_channel(). > > The new mbox_flush() API introduces a build-time dependency between the > TCU driver and the mailbox framework, so patches 1-9 would need to go > through one tree. Patch 9 was already acked by Greg, so I would suggest > that Jassi pick up the first 9 patches and I pick up patches 10-12 into > the Tegra tree. > > Changes in v3: > - add a patch from Bartosz Golaszewski to use devm_kstrdup_const() > - add a patch to use device-managed registration to simplify code > - introduce explicit mailbox flush API > > Changes in v2: > - address all of Pekka's comments regarding shared interrupts, registers > that don't exist on Tegra186 and shared mailbox directionality > - add a patch to enable the TCU in the 64-bit ARM default configuration > > Thanks, > Thierry > > [0]: https://lore.kernel.org/patchwork/project/lkml/list/?series=357641 > > Bartosz Golaszewski (1): > mailbox: tegra-hsp: use devm_kstrdup_const() > > Mikko Perttunen (5): > mailbox: Allow multiple controllers per device > dt-bindings: tegra186-hsp: Add shared mailboxes > dt-bindings: serial: Add bindings for nvidia,tegra194-tcu > arm64: tegra: Add nodes for TCU on Tegra194 > arm64: tegra: Mark TCU as primary serial port on Tegra194 P2888 > > Thierry Reding (6): > mailbox: Support blocking transfers in atomic context > mailbox: tegra-hsp: Add support for shared mailboxes > mailbox: tegra-hsp: Add suspend/resume support > mailbox: tegra-hsp: Use device-managed registration API > serial: Add Tegra Combined UART driver > arm64: defconfig: Enable Tegra TCU > > .../bindings/mailbox/nvidia,tegra186-hsp.txt | 30 +- > .../bindings/serial/nvidia,tegra194-tcu.txt | 35 ++ > .../arm64/boot/dts/nvidia/tegra194-p2888.dtsi | 2 +- > arch/arm64/boot/dts/nvidia/tegra194.dtsi | 38 +- > arch/arm64/configs/defconfig | 1 + > drivers/mailbox/mailbox.c | 31 +- > drivers/mailbox/tegra-hsp.c | 517 +++++++++++++++--- > drivers/tty/serial/Kconfig | 22 + > drivers/tty/serial/Makefile | 1 + > drivers/tty/serial/tegra-tcu.c | 298 ++++++++++ > include/dt-bindings/mailbox/tegra186-hsp.h | 11 + > include/linux/mailbox_client.h | 1 + > include/linux/mailbox_controller.h | 4 + > include/uapi/linux/serial_core.h | 3 + > 14 files changed, 903 insertions(+), 91 deletions(-) > create mode 100644 Documentation/devicetree/bindings/serial/nvidia,tegra194-tcu.txt > create mode 100644 drivers/tty/serial/tegra-tcu.c Hi Jassi, do you have any comments on this? Thierry
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