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authorqizhong cheng <qizhong.cheng@mediatek.com>2023-12-11 17:49:23 +0800
committerBjorn Helgaas <bhelgaas@google.com>2024-01-09 16:41:23 -0600
commit4e11c29873a8a296a20f99b3e03095e65ebf897d (patch)
treef23661404feacf15bb12bf1656d867cb30e4d898 /drivers/pci
parentb85ea95d086471afb4ad062012a4d73cd328fa86 (diff)
PCI: mediatek: Clear interrupt status before dispatching handler
We found a failure when using the iperf tool during WiFi performance testing, where some MSIs were received while clearing the interrupt status, and these MSIs cannot be serviced. The interrupt status can be cleared even if the MSI status remains pending. As such, given the edge-triggered interrupt type, its status should be cleared before being dispatched to the handler of the underling device. [kwilczynski: commit log, code comment wording] Link: https://lore.kernel.org/linux-pci/20231211094923.31967-1-jianjun.wang@mediatek.com Fixes: 43e6409db64d ("PCI: mediatek: Add MSI support for MT2712 and MT7622") Signed-off-by: qizhong cheng <qizhong.cheng@mediatek.com> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com> Signed-off-by: Krzysztof WilczyƄski <kwilczynski@kernel.org> [bhelgaas: rewrap comment] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: <stable@vger.kernel.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/controller/pcie-mediatek.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index 66a8f73296fc..48372013f26d 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -617,12 +617,18 @@ static void mtk_pcie_intr_handler(struct irq_desc *desc)
if (status & MSI_STATUS){
unsigned long imsi_status;
+ /*
+ * The interrupt status can be cleared even if the
+ * MSI status remains pending. As such, given the
+ * edge-triggered interrupt type, its status should
+ * be cleared before being dispatched to the
+ * handler of the underlying device.
+ */
+ writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
while ((imsi_status = readl(port->base + PCIE_IMSI_STATUS))) {
for_each_set_bit(bit, &imsi_status, MTK_MSI_IRQS_NUM)
generic_handle_domain_irq(port->inner_domain, bit);
}
- /* Clear MSI interrupt status */
- writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
}
}