From 36bfc3642b19a98f1302aed4437c331df9b481f0 Mon Sep 17 00:00:00 2001 From: Daniel Hodges Date: Fri, 6 Feb 2026 15:05:29 -0500 Subject: [PATCH] PCI: epf-mhi: Return 0, not remaining timeout, when eDMA ops complete pci_epf_mhi_edma_read() and pci_epf_mhi_edma_write() start DMA operations and wait for completion with a timeout. On successful completion, they previously returned the remaining timeout, which callers may treat as an error. In particular, mhi_ep_ring_add_element(), which calls pci_epf_mhi_edma_write() via mhi_cntrl->write_sync(), interprets any non-zero return value as failure. Return 0 on success instead of the remaining timeout to prevent mhi_ep_ring_add_element() from treating successful completion as an error. Fixes: 7b99aaaddabb ("PCI: epf-mhi: Add eDMA support") Signed-off-by: Daniel Hodges [mani: changed commit log as per https://lore.kernel.org/linux-pci/20260227191510.GA3904799@bhelgaas] Signed-off-by: Manivannan Sadhasivam Reviewed-by: Krishna Chaitanya Chundru Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260206200529.10784-1-git@danielhodges.dev --- drivers/pci/endpoint/functions/pci-epf-mhi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c index f9cf18aa5b342..7f5326925ed54 100644 --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c @@ -367,6 +367,8 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl, dev_err(dev, "DMA transfer timeout\n"); dmaengine_terminate_sync(chan); ret = -ETIMEDOUT; + } else { + ret = 0; } err_unmap: @@ -438,6 +440,8 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl, dev_err(dev, "DMA transfer timeout\n"); dmaengine_terminate_sync(chan); ret = -ETIMEDOUT; + } else { + ret = 0; } err_unmap: -- 2.47.3