PCI: Speed up device reset function
For all devices need to do function level reset, currently we need wait for
at least 200ms, which can be too long if we have lots of devices...
The patch checked pending bit before msleep() to skip some unnecessary
sleeping interval.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5737b8a..0b3e20f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2028,18 +2028,24 @@
pci_block_user_cfg_access(dev);
/* Wait for Transaction Pending bit clean */
+ pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);
+ if (!(status & PCI_EXP_DEVSTA_TRPND))
+ goto transaction_done;
+
msleep(100);
pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);
- if (status & PCI_EXP_DEVSTA_TRPND) {
- dev_info(&dev->dev, "Busy after 100ms while trying to reset; "
- "sleeping for 1 second\n");
- ssleep(1);
- pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);
- if (status & PCI_EXP_DEVSTA_TRPND)
- dev_info(&dev->dev, "Still busy after 1s; "
- "proceeding with reset anyway\n");
- }
+ if (!(status & PCI_EXP_DEVSTA_TRPND))
+ goto transaction_done;
+ dev_info(&dev->dev, "Busy after 100ms while trying to reset; "
+ "sleeping for 1 second\n");
+ ssleep(1);
+ pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status);
+ if (status & PCI_EXP_DEVSTA_TRPND)
+ dev_info(&dev->dev, "Still busy after 1s; "
+ "proceeding with reset anyway\n");
+
+transaction_done:
pci_write_config_word(dev, exppos + PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_BCR_FLR);
mdelay(100);
@@ -2066,18 +2072,24 @@
pci_block_user_cfg_access(dev);
/* Wait for Transaction Pending bit clean */
+ pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);
+ if (!(status & PCI_AF_STATUS_TP))
+ goto transaction_done;
+
msleep(100);
pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);
- if (status & PCI_AF_STATUS_TP) {
- dev_info(&dev->dev, "Busy after 100ms while trying to"
- " reset; sleeping for 1 second\n");
- ssleep(1);
- pci_read_config_byte(dev,
- cappos + PCI_AF_STATUS, &status);
- if (status & PCI_AF_STATUS_TP)
- dev_info(&dev->dev, "Still busy after 1s; "
- "proceeding with reset anyway\n");
- }
+ if (!(status & PCI_AF_STATUS_TP))
+ goto transaction_done;
+
+ dev_info(&dev->dev, "Busy after 100ms while trying to"
+ " reset; sleeping for 1 second\n");
+ ssleep(1);
+ pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);
+ if (status & PCI_AF_STATUS_TP)
+ dev_info(&dev->dev, "Still busy after 1s; "
+ "proceeding with reset anyway\n");
+
+transaction_done:
pci_write_config_byte(dev, cappos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
mdelay(100);