2022-11-01 00:24:48

by Smita Koralahalli

Subject: [PATCH 2/2] PCI:pciehp: Clear 10-bit tags unconditionally on a hot-plug event

Clear 10-bit tags unconditionally as there is no guarantee that the next
device inserted will support this feature.

Signed-off-by: Smita Koralahalli <[email protected]>
---
drivers/pci/pcie/dpc.c | 3 ++-
include/uapi/linux/pci_regs.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index e422876f51ad..8e02a32134ab 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -331,7 +331,8 @@ static void pciehp_handle_surprise_removal(struct pci_dev *pdev)
* and any newly added component may not be an ARI device.
*/
pcie_capability_clear_word(pdev, PCI_EXP_DEVCTL2,
- (PCI_EXP_DEVCTL2_ARI | PCI_EXP_DEVCTL2_ATOMIC_REQ));
+ (PCI_EXP_DEVCTL2_ARI | PCI_EXP_DEVCTL2_ATOMIC_REQ |
+ PCI_EXP_DEVCTL2_TAG_REQ_EN));

pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_TRIGGER);
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 57b8e2ffb1dd..65e1075b7db1 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -668,6 +668,7 @@
#define PCI_EXP_DEVCTL2_IDO_REQ_EN 0x0100 /* Allow IDO for requests */
#define PCI_EXP_DEVCTL2_IDO_CMP_EN 0x0200 /* Allow IDO for completions */
#define PCI_EXP_DEVCTL2_LTR_EN 0x0400 /* Enable LTR mechanism */
+#define PCI_EXP_DEVCTL2_TAG_REQ_EN 0x1000 /* Allow 10 Tags for Requester */
#define PCI_EXP_DEVCTL2_OBFF_MSGA_EN 0x2000 /* Enable OBFF Message type A */
#define PCI_EXP_DEVCTL2_OBFF_MSGB_EN 0x4000 /* Enable OBFF Message type B */
#define PCI_EXP_DEVCTL2_OBFF_WAKE_EN 0x6000 /* OBFF using WAKE# signaling */
--
2.17.1

2022-11-02 23:20:09

by Bjorn Helgaas

Subject: Re: [PATCH 2/2] PCI:pciehp: Clear 10-bit tags unconditionally on a hot-plug event

Update the subject line spacing to match the [1/2] patch (and previous
history for pciehp).

On Tue, Nov 01, 2022 at 12:07:19AM +0000, Smita Koralahalli wrote:
> Clear 10-bit tags unconditionally as there is no guarantee that the next
> device inserted will support this feature.