6.6-stable review patch. If anyone has any objections, please let me know.
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From: Brett Creeley brett.creeley@amd.com
commit d9e2f070d8af60f2c8c02b2ddf0a9e90b4e9220c upstream.
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 michal.swiatkowski@linux.intel.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Brett Creeley brett.creeley@amd.com Signed-off-by: Shannon Nelson shannon.nelson@amd.com Reviewed-by: Jacob Keller jacob.e.keller@intel.com Link: https://patch.msgid.link/20250421174606.3892-2-shannon.nelson@amd.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Alper Ak alperyasinak1@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- a/drivers/net/ethernet/amd/pds_core/core.c +++ b/drivers/net/ethernet/amd/pds_core/core.c @@ -413,10 +413,7 @@ int pdsc_setup(struct pdsc *pdsc, bool i if (err) return 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, --- 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