Commit b0d4bb97 authored by Shyam Sundar S K's avatar Shyam Sundar S K Committed by Hans de Goede
Browse files

platform/x86/amd: pmc: Write dummy postcode into the STB DRAM 



Based on the recommendation from the PMFW team in order to get the
recent telemetry data present on the STB DRAM the driver is required
to send one dummy write to the STB buffer, so it internally triggers
the PMFW to emit the latest telemetry data in the STB DRAM region.

Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarShyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20230206150855.1938810-3-Shyam-sundar.S-k@amd.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 1ecfd309

drivers/platform/x86/amd/pmc.c

+6 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#define AMD_PMC_STB_S2IDLE_PREPARE	0xC6000001

#define AMD_PMC_STB_S2IDLE_RESTORE	0xC6000002

#define AMD_PMC_STB_S2IDLE_CHECK	0xC6000003

#define AMD_PMC_STB_DUMMY_PC		0xC6000007



/* STB S2D(Spill to DRAM) has different message port offset */

#define STB_SPILL_TO_DRAM		0xBE
@@ -250,6 +251,11 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) 
	u32 *buf, fsize, num_samples, stb_rdptr_offset = 0;

	int ret;



	/* Write dummy postcode while reading the STB buffer */

	ret = amd_pmc_write_stb(dev, AMD_PMC_STB_DUMMY_PC);

	if (ret)

		dev_err(dev->dev, "error writing to STB: %d\n", ret);



	buf = kzalloc(S2D_TELEMETRY_BYTES_MAX, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;