From d9e2f070d8af60f2c8c02b2ddf0a9e90b4e9220c Mon Sep 17 00:00:00 2001 From: Brett Creeley Date: Mon, 21 Apr 2025 10:46:03 -0700 Subject: [PATCH] pds_core: Prevent possible adminq overflow/stuck condition The pds_core's adminq is protected by the adminq_lock, which prevents more than 1 command to be posted onto it at any one time. This makes it so the client drivers cannot simultaneously post adminq commands. However, the completions happen in a different context, which means multiple adminq commands can be posted sequentially and all waiting on completion. On the FW side, the backing adminq request queue is only 16 entries long and the retry mechanism and/or overflow/stuck prevention is lacking. This can cause the adminq to get stuck, so commands are no longer processed and completions are no longer sent by the FW. As an initial fix, prevent more than 16 outstanding adminq commands so there's no way to cause the adminq from getting stuck. This works because the backing adminq request queue will never have more than 16 pending adminq commands, so it will never overflow. This is done by reducing the adminq depth to 16. Fixes: 45d76f492938 ("pds_core: set up device and adminq") Reviewed-by: Michal Swiatkowski Reviewed-by: Simon Horman Signed-off-by: Brett Creeley Signed-off-by: Shannon Nelson Reviewed-by: Jacob Keller Link: https://patch.msgid.link/20250421174606.3892-2-shannon.nelson@amd.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/amd/pds_core/core.c | 5 +---- drivers/net/ethernet/amd/pds_core/core.h | 2 +- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/amd/pds_core/core.c b/drivers/net/ethernet/amd/pds_core/core.c index 1eb0d92786f71..55163457f12be 100644 --- a/drivers/net/ethernet/amd/pds_core/core.c +++ b/drivers/net/ethernet/amd/pds_core/core.c @@ -325,10 +325,7 @@ static int pdsc_core_init(struct pdsc *pdsc) size_t sz; int err; - /* Scale the descriptor ring length based on number of CPUs and VFs */ - numdescs = max_t(int, PDSC_ADMINQ_MIN_LENGTH, num_online_cpus()); - numdescs += 2 * pci_sriov_get_totalvfs(pdsc->pdev); - numdescs = roundup_pow_of_two(numdescs); + numdescs = PDSC_ADMINQ_MAX_LENGTH; err = pdsc_qcq_alloc(pdsc, PDS_CORE_QTYPE_ADMINQ, 0, "adminq", PDS_CORE_QCQ_F_CORE | PDS_CORE_QCQ_F_INTR, numdescs, diff --git a/drivers/net/ethernet/amd/pds_core/core.h b/drivers/net/ethernet/amd/pds_core/core.h index 0bf320c430836..199473112c295 100644 --- a/drivers/net/ethernet/amd/pds_core/core.h +++ b/drivers/net/ethernet/amd/pds_core/core.h @@ -16,7 +16,7 @@ #define PDSC_WATCHDOG_SECS 5 #define PDSC_QUEUE_NAME_MAX_SZ 16 -#define PDSC_ADMINQ_MIN_LENGTH 16 /* must be a power of two */ +#define PDSC_ADMINQ_MAX_LENGTH 16 /* must be a power of two */ #define PDSC_NOTIFYQ_LENGTH 64 /* must be a power of two */ #define PDSC_TEARDOWN_RECOVERY false #define PDSC_TEARDOWN_REMOVING true -- 2.39.5