[PATCH i-g-t] tests/intel/xe_pm: Test to validate vram-sr through Mods during host s2idle

[Anirban, Sk]

Hi Soham,

On 02-06-2025 16:33, Soham Purkait wrote:
>      Add test to validate vram-sr through Mods during host s2idle. It checks
> whether vram self refresh capability is supported through debugfs node and
> then introduce host s2idle to check ModS residency to confirm vram self
> refresh capability upon success.
>
> Signed-off-by: Soham Purkait <soham.purkait at intel.com>
> ---
>   tests/intel/xe_pm.c | 99 ++++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 98 insertions(+), 1 deletion(-)
>
> diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
> index 6eb21d5ec..322b22eb0 100644
> --- a/tests/intel/xe_pm.c
> +++ b/tests/intel/xe_pm.c
> @@ -10,9 +10,10 @@
>    * Sub-category: Suspend-resume tests
>    * Test category: functionality test
>    */
> -
> +#include <ctype.h>
>   #include <limits.h>
>   #include <fcntl.h>
> +#include <stddef.h>
>   #include <string.h>
>   
>   #include "igt.h"
> @@ -413,6 +414,46 @@ child_exec(void *arguments)
>   	return NULL;
>   }
>   
> +static char *read_content_line(const char *content, const char *prefix)
> +{
> +	const char *line_start = content;
> +	char line[1024];
> +	char *result;
> +	size_t len;
> +
> +	while (*line_start) {
> +		const char *line_end = strchr(line_start, '\n');
> +		size_t line_len = line_end ? (size_t)(line_end - line_start) : strlen(line_start);
> +
> +		if (line_len >= sizeof(line))
> +			line_len = sizeof(line) - 1;
> +
> +		memcpy(line, line_start, line_len);
> +		line[line_len] = '\0';
> +
> +		if (strstr(line, prefix)) {
> +			char *colon = strchr(line, ':');
> +
> +			if (colon) {
> +				colon++;
> +				while (isspace((unsigned char)*colon))
> +					colon++;
> +
> +				result = strdup(colon);
> +				len = strlen(result);
> +				if (len > 0 && result[len - 1] == '\n')
> +					result[len - 1] = '\0';
> +
> +				return result;
> +			}
> +		}
> +		line_start = line_end ? line_end + 1 : NULL;
> +		if (!line_start)
> +			break;
> +	}
> +	return NULL;
> +}
imho this function is not required, explained below.
> +
>   /**
>    * SUBTEST: %s-basic
>    * Description: test CPU/GPU in and out of s/d state from %arg[1]
> @@ -777,6 +818,57 @@ static void test_mocs_suspend_resume(device_t device, enum igt_suspend_state s_s
>   	}
>   }
>   
> +/**
> + * SUBTEST: vrsr-capability-during-host-s2idle
> + * Functionality: pm - vram-sr
> + * Description: Test to validate vram self refresh through
> + * ModS residency counter during host s2idle
> + */
> +
> +static void test_vrsr_capability_during_host_s2idle(device_t device)
> +{
> +	u32 bo, placement;
> +	u64 s2idle_start_mods, s2idle_end_mods;
> +	int dir, ret;
> +	char buf[4096] = {0};
You can reduce the side, buf[256] should be enough to store data.
> +	char *result;
> +	void *map;
> +
> +	dir = igt_debugfs_dir(device.fd_xe);
> +	ret = igt_debugfs_simple_read(dir, "vrsr_capable",
> +				      buf, sizeof(buf));
> +	igt_assert_f(ret >= 0, "vrsr_capable node is not present in debugfs.\n");
> +	igt_assert_f(strstr(buf, "true"), "VRSR capability is not supported.");
> +
> +	placement = vram_memory(device.fd_xe, 0);
> +#define XE_BO_SIZE (350 * 1024 * 1024)
define these macros at the top.
> +	bo = xe_bo_create(device.fd_xe, 0, XE_BO_SIZE, placement, 0);
> +	map = xe_bo_map(device.fd_xe, bo, XE_BO_SIZE);
> +	memset(map, 0, XE_BO_SIZE);
> +
> +	ret = igt_debugfs_simple_read(dir, "gtidle/dgfx_pkg_residencies", buf, sizeof(buf));
> +	igt_assert_f(ret >= 0, "dgfx_pkg_residencies node is not present in debugfs.\n");
> +
> +#define MODS_PREFIX "ModS"
same as above.
> +	result = read_content_line(buf, MODS_PREFIX);
Just to read the package residency here, you can use sscanf. For more 
details please refer to the function read_mods here:
https://patchwork.freedesktop.org/patch/660150/?series=149557&rev=2
> +	igt_assert(result);
> +	s2idle_start_mods = (uint64_t)strtoull(result, NULL, 10);
> +	free(result);
> +
> +	igt_system_suspend_autoresume(SUSPEND_STATE_FREEZE, SUSPEND_TEST_NONE);
> +	munmap(map, XE_BO_SIZE);
> +	memset(buf, 0, sizeof(buf));
> +	ret = igt_debugfs_simple_read(dir, "gtidle/dgfx_pkg_residencies", buf, sizeof(buf));
> +
> +	result = read_content_line(buf, MODS_PREFIX);
same as above.
> +	igt_assert(result);
> +
> +	s2idle_end_mods = (uint64_t)strtoull(result, NULL, 10);
> +	free(result);
> +
> +	igt_assert(s2idle_start_mods != s2idle_end_mods);
Maybe we can check if the end counter is greater than the first one or not.

Regards,
Anirban
> +}
> +
>   igt_main
>   {
>   	device_t device;
> @@ -936,6 +1028,11 @@ igt_main
>   		test_vram_d3cold_threshold(device, sysfs_fd);
>   	}
>   
> +	igt_describe("Validate VRAM self refresh capability during host s2idle");
> +	igt_subtest("vrsr-capability-during-host-s2idle") {
> +		test_vrsr_capability_during_host_s2idle(device);
> +	}
> +
>   	igt_fixture {
>   		close(sysfs_fd);
>   		igt_pm_set_d3cold_allowed(device.pci_slot_name, d3cold_allowed);