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

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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: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Shyam 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: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Shyam Sundar S K 2023-02-06 20:38:53 +05:30 committed by Hans de Goede
parent 1ecfd30960
commit b0d4bb9735
1 changed files with 6 additions and 0 deletions
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6
drivers/platform/x86/amd/pmc.c
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@ -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;