[PATCH i-g-t v1] tests/intel/xe_pm: Introduce i2c subtests

[Lucas De Marchi]

On Fri, Mar 21, 2025 at 11:02:05PM +0530, Raag Jadav wrote:
>Introduce subtests for i2c adapter which is used to control on-board
>OEM sensors on selected devices. This will test D3hot/D3cold transition
>after i2c adapter access for the devices that support it.
>
>Signed-off-by: Raag Jadav <raag.jadav at intel.com>
>---
> tests/intel/xe_pm.c | 95 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 95 insertions(+)
>
>diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
>index 19b0d5ef7..233e63d17 100644
>--- a/tests/intel/xe_pm.c
>+++ b/tests/intel/xe_pm.c
>@@ -11,12 +11,18 @@
>  * Test category: functionality test
>  */
>
>+#include <dirent.h>
> #include <limits.h>
> #include <fcntl.h>
> #include <string.h>
>+#include <sys/ioctl.h>
>+
>+#include <linux/i2c-dev.h>
>+#include <linux/i2c.h>
>
> #include "igt.h"
> #include "lib/igt_device.h"
>+#include "lib/igt_kmod.h"
> #include "lib/igt_pm.h"
> #include "lib/igt_sysfs.h"
> #include "lib/igt_syncobj.h"
>@@ -774,6 +780,88 @@ static void test_mocs_suspend_resume(device_t device, enum igt_suspend_state s_s
> 	}
> }
>
>+static int find_i2c_index(device_t device, int sysfs_fd)

s/index/adapter/


I'm very confused here... how is this related to power management to be
a subtest in xe_pm?

Back in the days when I was working with IOT, it used to be the case
that distros weren't enabling spidev/i2c-dev. Did things change and we
can use them in what's used for CI?

>+{
>+	int adapter_fd, i2c_index = -1;
>+	struct dirent *dirent;
>+	char adapter[32];
>+	DIR *dir;
>+
>+	/* Make sure the /dev/i2c-* files exist */
>+	igt_require(igt_kmod_load("i2c-dev", NULL) == 0);
>+
>+	snprintf(adapter, sizeof(adapter) - 1, "%s.%hu", "device/i2c_designware",
>+		 (device.pci_xe->bus << 8) | (device.pci_xe->dev));
>+	adapter_fd = openat(sysfs_fd, adapter, O_RDONLY);
>+	igt_require_fd(adapter_fd);
>+
>+	dir = fdopendir(adapter_fd);
>+	igt_assert(dir);
>+
>+	/* Find the i2c device node index */
>+	while ((dirent = readdir(dir))) {
>+		if (strncmp(dirent->d_name, "i2c-", 4) == 0) {
>+			sscanf(dirent->d_name, "i2c-%d", &i2c_index);
>+			break;
>+		}
>+	}
>+
>+	closedir(dir);
>+	close(adapter_fd);
>+	return i2c_index;
>+}
>+
>+/**
>+ * SUBTEST: %s-i2c
>+ * Description:
>+ * 	Validate whether the device is able to suspend after i2c adapter access.
>+ * Functionality: pm-d3
>+ * GPU requirements: D3 feature should be supported
>+ *
>+ * arg[1]:
>+ *
>+ * @d3hot:	d3hot
>+ * @d3cold:	d3cold
>+ */
>+static bool i2c_test(device_t device, int sysfs_fd)
>+{
>+	/* AMC slave details */
>+	uint8_t addr = 0x40, reg = 0x0, buf;

as part of the AMC protocol, it'd be better to have proper defines.

>+	int i2c_index, i2c_fd;
>+	char i2c_dev[16];
>+	struct i2c_msg msgs[] = {
>+		{
>+			.addr = addr,
>+			.flags = 0,
>+			.len = sizeof(reg),
>+			.buf = &reg,
>+		}, {
>+			.addr = addr,
>+			.flags = I2C_M_RD,
>+			.len = sizeof(buf),
>+			.buf = &buf,
>+		}
>+	};
>+	struct i2c_rdwr_ioctl_data msgset = {
>+		.msgs = msgs,
>+		.nmsgs = ARRAY_SIZE(msgs),
>+	};
>+
>+	i2c_index = find_i2c_index(device, sysfs_fd);
>+	igt_assert(i2c_index >= 0);
>+
>+	snprintf(i2c_dev, sizeof(i2c_dev) - 1, "/dev/i2c-%hhd", i2c_index);
>+	i2c_fd = open(i2c_dev, O_RDWR);
>+	igt_assert_fd(i2c_fd);


wouldn't this fail if we don't have the needed kernel config or

>+
>+	/* Perform an i2c transaction to trigger adapter wake */
>+	igt_info("Accessing slave 0x%hhx on %s\n", addr, i2c_dev);
>+	igt_assert(igt_ioctl(i2c_fd, I2C_RDWR, &msgset) >= 0);

or... the platform doesn't support talking to amc. Usually these cases
are skips, not failures.

Lucas De Marchi

>+
>+	close(i2c_fd);
>+	return true;
>+}
>+
> igt_main
> {
> 	device_t device;
>@@ -881,6 +969,13 @@ igt_main
> 			cleanup_d3(device);
> 		}
>
>+		igt_subtest_f("%s-i2c", d->name) {
>+			igt_assert(setup_d3(device, d->state));
>+			igt_assert(i2c_test(device, sysfs_fd));
>+			igt_assert(in_d3(device, d->state));
>+			cleanup_d3(device);
>+		}
>+
> 		igt_subtest_f("%s-multiple-execs", d->name) {
> 			igt_assert(setup_d3(device, d->state));
> 			test_exec(device, 16, 32, NO_SUSPEND, d->state, 0);
>-- 
>2.34.1
>