The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 688d2eb4c6fcfdcdaed0592f9df9196573ff5ce2 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024120649-cranium-uncle-f7f1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 688d2eb4c6fcfdcdaed0592f9df9196573ff5ce2 Mon Sep 17 00:00:00 2001 From: Zijun Hu quic_zijuhu@quicinc.com Date: Thu, 7 Nov 2024 08:53:09 +0800 Subject: [PATCH] PCI: endpoint: Clear secondary (not primary) EPC in pci_epc_remove_epf() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

In addition to a primary endpoint controller, an endpoint function may be associated with a secondary endpoint controller, epf->sec_epc, to provide NTB (non-transparent bridge) functionality.

Previously, pci_epc_remove_epf() incorrectly cleared epf->epc instead of epf->sec_epc when removing from the secondary endpoint controller.

Extend the epc->list_lock coverage and clear either epf->epc or epf->sec_epc as indicated.

Link: https://lore.kernel.org/r/20241107-epc_rfc-v2-2-da5b6a99a66f@quicinc.com Fixes: 63840ff53223 ("PCI: endpoint: Add support to associate secondary EPC with EPF") Signed-off-by: Zijun Hu quic_zijuhu@quicinc.com Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org [mani: reworded subject and description] Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Cc: stable@vger.kernel.org

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c index 21af2dbacc33..bed7c7d1fe3c 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -746,18 +746,18 @@ void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf, if (IS_ERR_OR_NULL(epc) || !epf) return;

+ mutex_lock(&epc->list_lock); if (type == PRIMARY_INTERFACE) { func_no = epf->func_no; list = &epf->list; + epf->epc = NULL; } else { func_no = epf->sec_epc_func_no; list = &epf->sec_epc_list; + epf->sec_epc = NULL; } - - mutex_lock(&epc->list_lock); clear_bit(func_no, &epc->function_num_map); list_del(list); - epf->epc = NULL; mutex_unlock(&epc->list_lock); } EXPORT_SYMBOL_GPL(pci_epc_remove_epf);