Hi All,
I am trying kexec -e with latest kernel i.e. Linux-5.5.0-rc4. Here
second kernel is not able to detect/mount hard-disk having root file
system (INTEL SSDSC2BB240G7).
[ 279.690575] ata1: softreset failed (1st FIS failed)
[ 279.695446] ata1: limiting SATA link speed to 3.0 Gbps
[ 280.910020] ata1: SATA link down (SStatus 0 SControl 320)
[ 282.626018] ata1: SATA link down (SStatus 0 SControl 300)
[ 282.631409] ata1: link online but 1 devices misclassified, retrying
[ 282.637665] ata1: reset failed (errno=-11), retrying in 9 secs
[ 298.294546] ata1: failed to reset engine (errno=-5)
[ 302.042967] ata1: softreset failed (1st FIS failed)
[ 308.798609] ata1: failed to reset engine (errno=-5)
[ 337.546605] ata1: softreset failed (1st FIS failed)
[ 337.551475] ata1: limiting SATA link speed to 3.0 Gbps
[ 338.766022] ata1: SATA link down (SStatus 0 SControl 320)
[ 339.270943] ata1: EH pending after 5 tries, giving up
I found following two workaround for this issue.
A) Define ".shutdown" in driver/ata/ahci.c.
reboot --> kernel_kexec() --> kernel_restart_prepare() -->
device_shutdown() --> pci_device_shutdown() --> ahci_shutdown_one()
--> new function
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 4bfd1b14b390..50a101002885 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -81,6 +81,7 @@ enum board_ids {
static int ahci_init_one(struct pci_dev *pdev, const struct
pci_device_id *ent);
static void ahci_remove_one(struct pci_dev *dev);
+static void ahci_shutdown_one(struct pci_dev *dev);
static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
unsigned long deadline);
static int ahci_avn_hardreset(struct ata_link *link, unsigned int *class,
@@ -606,6 +607,7 @@ static struct pci_driver ahci_pci_driver = {
.id_table = ahci_pci_tbl,
.probe = ahci_init_one,
.remove = ahci_remove_one,
+ .shutdown = ahci_shutdown_one,
.driver = {
.pm = &ahci_pci_pm_ops,
},
+static void ahci_shutdown_one(struct pci_dev *pdev)
+{
+ pm_runtime_get_noresume(&pdev->dev);
+ ata_pci_remove_one(pdev);
+}
+
Note: After defining shutdown, error related to file-system write
seen. Looks like even after device_shutdown, file system related
transaction goes to disk.
B)) Commenting of pci_clear_master() from pci_device_shutdown()
reboot --> kernel_kexec() --> kernel_restart_prepare() -->
device_shutdown() --> pci_device_shutdown()
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 0454ca0e4e3f..ddffaa9321bb 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -481,8 +481,10 @@ static void pci_device_shutdown(struct device *dev)
/*
* If this is a kexec reboot, turn off Bus Master bit on the
@@ -491,8 +493,16 @@ static void pci_device_shutdown(struct device *dev)
* If it is not a kexec reboot, firmware will hit the PCI
* devices with big hammer and stop their DMA any way.
*/
- if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
- pci_clear_master(pci_dev);
Here pci_dev current_state. It is "0" i.e. D0.
>From A and B. Looks like even after pci_clear_master(), Some DMA
transactions going on PCIe device causing device in unstable.
Not sure if this is the reason and how to solve this problem.
Any help/guidance will help me in moving forward.
Thanks!!
--prabhakar (pk)
