Re: [PATCH v4 2/3] PCI/DPC: Run recovery on device that detected the error
From: Shuai Xue
Date: Thu Jun 19 2025 - 02:29:13 EST
在 2025/6/12 18:31, Manivannan Sadhasivam 写道:
On Mon, Feb 17, 2025 at 10:42:17AM +0800, Shuai Xue wrote:
The current implementation of pcie_do_recovery() assumes that the
recovery process is executed on the device that detected the error.
s/on/for
However, the DPC driver currently passes the error port that experienced
the DPC event to pcie_do_recovery().
Use the SOURCE ID register to correctly identify the device that
detected the error. When passing the error device, the
pcie_do_recovery() will find the upstream bridge and walk bridges
potentially AER affected. And subsequent patches will be able to
s/patches/commits
Will fix the typos.
accurately access AER status of the error device.
Should not observe any functional changes.
Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
---
drivers/pci/pci.h | 2 +-
drivers/pci/pcie/dpc.c | 28 ++++++++++++++++++++++++----
drivers/pci/pcie/edr.c | 7 ++++---
3 files changed, 29 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 01e51db8d285..870d2fbd6ff2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -572,7 +572,7 @@ struct rcec_ea {
void pci_save_dpc_state(struct pci_dev *dev);
void pci_restore_dpc_state(struct pci_dev *dev);
void pci_dpc_init(struct pci_dev *pdev);
-void dpc_process_error(struct pci_dev *pdev);
+struct pci_dev *dpc_process_error(struct pci_dev *pdev);
pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);
bool pci_dpc_recovered(struct pci_dev *pdev);
unsigned int dpc_tlp_log_len(struct pci_dev *dev);
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 1a54a0b657ae..ea3ea989afa7 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -253,10 +253,20 @@ static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev,
return 1;
}
-void dpc_process_error(struct pci_dev *pdev)
+/**
+ * dpc_process_error - handle the DPC error status
+ * @pdev: the port that experienced the containment event
+ *
+ * Return the device that detected the error.
s/Return/Return:
+ *
+ * NOTE: The device reference count is increased, the caller must decrement
+ * the reference count by calling pci_dev_put().
+ */
+struct pci_dev *dpc_process_error(struct pci_dev *pdev)
{
u16 cap = pdev->dpc_cap, status, source, reason, ext_reason;
struct aer_err_info info;
+ struct pci_dev *err_dev;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source);
@@ -279,6 +289,13 @@ void dpc_process_error(struct pci_dev *pdev)
"software trigger" :
"reserved error");
+ if (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_NFE ||
+ reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE)
+ err_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+ PCI_BUS_NUM(source), source & 0xff);
+ else
+ err_dev = pci_dev_get(pdev);
+
/* show RP PIO error detail information */
if (pdev->dpc_rp_extensions &&
reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_IN_EXT &&
@@ -291,6 +308,8 @@ void dpc_process_error(struct pci_dev *pdev)
pci_aer_clear_nonfatal_status(pdev);
pci_aer_clear_fatal_status(pdev);
}
+
+ return err_dev;
}
static void pci_clear_surpdn_errors(struct pci_dev *pdev)
@@ -346,7 +365,7 @@ static bool dpc_is_surprise_removal(struct pci_dev *pdev)
static irqreturn_t dpc_handler(int irq, void *context)
{
- struct pci_dev *err_port = context;
+ struct pci_dev *err_port = context, *err_dev;
/*
* According to PCIe r6.0 sec 6.7.6, errors are an expected side effect
@@ -357,10 +376,11 @@ static irqreturn_t dpc_handler(int irq, void *context)
return IRQ_HANDLED;
}
- dpc_process_error(err_port);
+ err_dev = dpc_process_error(err_port);
/* We configure DPC so it only triggers on ERR_FATAL */
- pcie_do_recovery(err_port, pci_channel_io_frozen, dpc_reset_link);
+ pcie_do_recovery(err_dev, pci_channel_io_frozen, dpc_reset_link);
+ pci_dev_put(err_dev);
return IRQ_HANDLED;
}
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
index 521fca2f40cb..088f3e188f54 100644
--- a/drivers/pci/pcie/edr.c
+++ b/drivers/pci/pcie/edr.c
@@ -150,7 +150,7 @@ static int acpi_send_edr_status(struct pci_dev *pdev, struct pci_dev *edev,
static void edr_handle_event(acpi_handle handle, u32 event, void *data)
{
- struct pci_dev *pdev = data, *err_port;
+ struct pci_dev *pdev = data, *err_port, *err_dev;
pci_ers_result_t estate = PCI_ERS_RESULT_DISCONNECT;
u16 status;
@@ -190,7 +190,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
goto send_ost;
}
- dpc_process_error(err_port);
+ err_dev = dpc_process_error(err_port);
pci_aer_raw_clear_status(err_port);
/*
@@ -198,7 +198,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
* or ERR_NONFATAL, since the link is already down, use the FATAL
* error recovery path for both cases.
*/
- estate = pcie_do_recovery(err_port, pci_channel_io_frozen, dpc_reset_link);
+ estate = pcie_do_recovery(err_dev, pci_channel_io_frozen, dpc_reset_link);
send_ost:
@@ -216,6 +216,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
}
pci_dev_put(err_port);
+ pci_dev_put(err_dev);
err_dev is not a valid pointer before calling dpc_process_error(). So either
initialize it with NULL or only call it in error paths after
dpc_process_error().
And btw, pci_dev_put(err_dev) should come before pci_dev_put(err_port).
- Mani
You are right.
Will send a new patch to fix it.
Thanks.
Shuai