Comments
Patch
===================================================================
@@ -16,6 +16,7 @@
#include <linux/pm.h>
#include <linux/init.h>
#include <linux/slab.h>
+#include <linux/jiffies.h>
#include <linux/pci-aspm.h>
#include "../pci.h"
@@ -161,11 +162,12 @@ static void pcie_check_clock_pm(struct p
*/
static void pcie_aspm_configure_common_clock(struct pci_dev *pdev)
{
- int pos, child_pos;
+ int pos, child_pos, i = 0;
u16 reg16 = 0;
struct pci_dev *child_dev;
int same_clock = 1;
-
+ unsigned long start_jiffies;
+ u16 child_regs[8], parent_reg;
/*
* all functions of a slot should have the same Slot Clock
* Configuration, so just check one function
@@ -191,16 +193,19 @@ static void pcie_aspm_configure_common_c
child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
®16);
+ child_regs[i] = reg16;
if (same_clock)
reg16 |= PCI_EXP_LNKCTL_CCC;
else
reg16 &= ~PCI_EXP_LNKCTL_CCC;
pci_write_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
reg16);
+ i++;
}
/* Configure upstream component */
pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, ®16);
+ parent_reg = reg16;
if (same_clock)
reg16 |= PCI_EXP_LNKCTL_CCC;
else
@@ -212,12 +217,30 @@ static void pcie_aspm_configure_common_c
pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
/* Wait for link training end */
- while (1) {
+ /* break out after waiting for 1 second */
+ start_jiffies = jiffies;
+ while ((jiffies - start_jiffies) < HZ) {
pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, ®16);
if (!(reg16 & PCI_EXP_LNKSTA_LT))
break;
cpu_relax();
}
+ /* training failed -> recover */
+ if ((jiffies - start_jiffies) >= HZ) {
+ dev_printk (KERN_ERR, &pdev->dev, "ASPM: Could not configure"
+ " common clock\n");
+ i = 0;
+ list_for_each_entry(child_dev, &pdev->subordinate->devices,
+ bus_list) {
+ child_pos = pci_find_capability(child_dev,
+ PCI_CAP_ID_EXP);
+ pci_write_config_word(child_dev,
+ child_pos + PCI_EXP_LNKCTL,
+ child_regs[i]);
+ i++;
+ }
+ pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, parent_reg);
+ }
}
/*
Hi Jesse, can you add this one, please. I adjusted the patch to suggestions from Matthew and Shaohua, thus added their Signed-offs. This should still go into .28 as it makes machines boot which now freeze since the ASPM patch was introduced. Thanks, Thomas ---- PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch Makes a Compaq 6735s boot reliably again which hang in the loop on some boots. Give the link one second to train, otherwise break out of the loop and reset the previously set clock bits. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org> --- drivers/pci/pcie/aspm.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html