Hi Enrico, On Wed, Oct 03, 2018 at 11:45:06AM -0700, Enrico Granata wrote: > From: Enrico Granata <egran...@chromium.org> > > This commit allows cros_ec_lpc to register a direct IRQ instead of relying > on the ACPI notification chain to receive MKBP events. > > This change is done in the interest of allowing reduced jitter in the > communication path between the CrOS EC and the host for receiving sensor > data. > > Signed-off-by: Enrico Granata <egran...@chromium.org>
Applied for v4.20. Thanks!
Benson
> ---
> drivers/platform/chrome/cros_ec_lpc.c | 21 +++++++++++++++++----
> 1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_lpc.c
> b/drivers/platform/chrome/cros_ec_lpc.c
> index 31c8b8c49e45..07eea608915e 100644
> --- a/drivers/platform/chrome/cros_ec_lpc.c
> +++ b/drivers/platform/chrome/cros_ec_lpc.c
> @@ -25,6 +25,7 @@
> #include <linux/dmi.h>
> #include <linux/delay.h>
> #include <linux/io.h>
> +#include <linux/interrupt.h>
> #include <linux/mfd/cros_ec.h>
> #include <linux/mfd/cros_ec_commands.h>
> #include <linux/mfd/cros_ec_lpc_reg.h>
> @@ -248,7 +249,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
> acpi_status status;
> struct cros_ec_device *ec_dev;
> u8 buf[2];
> - int ret;
> + int irq, ret;
>
> if (!devm_request_region(dev, EC_LPC_ADDR_MEMMAP, EC_MEMMAP_SIZE,
> dev_name(dev))) {
> @@ -287,6 +288,18 @@ static int cros_ec_lpc_probe(struct platform_device
> *pdev)
> sizeof(struct ec_response_get_protocol_info);
> ec_dev->dout_size = sizeof(struct ec_host_request);
>
> + /*
> + * Some boards do not have an IRQ allotted for cros_ec_lpc,
> + * which makes ENXIO an expected (and safe) scenario.
> + */
> + irq = platform_get_irq(pdev, 0);
> + if (irq > 0)
> + ec_dev->irq = irq;
> + else if (irq != -ENXIO) {
> + dev_err(dev, "couldn't retrieve IRQ number (%d)\n", irq);
> + return irq;
> + }
> +
> ret = cros_ec_register(ec_dev);
> if (ret) {
> dev_err(dev, "couldn't register ec_dev (%d)\n", ret);
> @@ -294,11 +307,11 @@ static int cros_ec_lpc_probe(struct platform_device
> *pdev)
> }
>
> /*
> - * Connect a notify handler to process MKBP messages if we have a
> - * companion ACPI device.
> + * If we have a companion ACPI device and no dedicated IRQ
> + * connect a notify handler to process MKBP messages.
> */
> adev = ACPI_COMPANION(dev);
> - if (adev) {
> + if (adev && ec_dev->irq <= 0) {
> status = acpi_install_notify_handler(adev->handle,
> ACPI_ALL_NOTIFY,
> cros_ec_lpc_acpi_notify,
> --
> 2.19.0.605.g01d371f741-goog
>
--
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
ble...@google.com
Chromium OS Project
ble...@chromium.org
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