From cbb32ff92f8a62212e0f7384b1de986ced92082b Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 21 Jul 2026 13:17:52 -0500 Subject: platform/x86/amd/pmc: Fix msg_port restoration in amd_stb_debugfs_open_v2() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit amd_stb_debugfs_open_v2() switches dev->msg_port to MSG_PORT_S2D to query S2D telemetry but only restores it to MSG_PORT_PMC on one path. The early return on the dump_custom_stb path (and the error/allocation returns) leave the port stuck on MSG_PORT_S2D, so subsequent SMU communication - including the s2idle prepare/restore handlers - is directed at the wrong mailbox. Consolidate the exit path through a single label so the message port is always restored, mirroring the fix in amd_stb_s2d_init(). Reported-by: sashiko.dev Link: https://sashiko.dev/#/patchset/20260717162023.956346-1-mario.limonciello%40amd.com Fixes: 2851f4f8ed4e ("platform/x86/amd/pmc: Define enum for S2D/PMC msg_port and add helper function") Cc: stable@vger.kernel.org Signed-off-by: Mario Limonciello Link: https://patch.msgid.link/20260721181756.143084-3-mario.limonciello@amd.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- drivers/platform/x86/amd/pmc/mp1_stb.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/platform/x86/amd/pmc/mp1_stb.c b/drivers/platform/x86/amd/pmc/mp1_stb.c index 83645c0a8d78..90b8a5cebfa8 100644 --- a/drivers/platform/x86/amd/pmc/mp1_stb.c +++ b/drivers/platform/x86/amd/pmc/mp1_stb.c @@ -157,7 +157,7 @@ static int amd_stb_debugfs_open_v2(struct inode *inode, struct file *filp) struct amd_pmc_dev *dev = filp->f_inode->i_private; u32 fsize, num_samples, val, stb_rdptr_offset = 0; struct amd_stb_v2_data *stb_data_arr; - int ret; + int ret = 0; /* Write dummy postcode while reading the STB buffer */ ret = amd_stb_write(dev, AMD_PMC_STB_DUMMY_PC); @@ -176,22 +176,24 @@ static int amd_stb_debugfs_open_v2(struct inode *inode, struct file *filp) * the enhanced dram size. Note that we land here only for the * platforms that support enhanced dram size reporting. */ - if (dump_custom_stb) - return amd_stb_handle_efr(filp); + if (dump_custom_stb) { + ret = amd_stb_handle_efr(filp); + goto out; + } /* Get the num_samples to calculate the last push location */ ret = amd_pmc_send_cmd(dev, S2D_NUM_SAMPLES, &num_samples, dev->stb_arg.s2d_msg_id, true); - /* Clear msg_port for other SMU operation */ - dev->msg_port = MSG_PORT_PMC; if (ret) { dev_err(dev->dev, "error: S2D_NUM_SAMPLES not supported : %d\n", ret); - return ret; + goto out; } fsize = min(num_samples, S2D_TELEMETRY_BYTES_MAX); stb_data_arr = kmalloc_flex(*stb_data_arr, data, fsize); - if (!stb_data_arr) - return -ENOMEM; + if (!stb_data_arr) { + ret = -ENOMEM; + goto out; + } stb_data_arr->size = fsize; @@ -214,7 +216,10 @@ static int amd_stb_debugfs_open_v2(struct inode *inode, struct file *filp) filp->private_data = stb_data_arr; - return 0; +out: + /* Restore the default message port for subsequent SMU operations */ + dev->msg_port = MSG_PORT_PMC; + return ret; } static ssize_t amd_stb_debugfs_read_v2(struct file *filp, char __user *buf, size_t size, -- cgit v1.2.3