[PATCH 2/2] xen-pciback: also support disabling of bus-mastering and memory-write-invalidate

From: Jan Beulich
Date: Wed Mar 11 2015 - 09:52:08 EST


It's not clear to me why only the enabling operation got handled so
far.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
drivers/xen/xen-pciback/conf_space_header.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

--- 4.0-rc3-xen-pciback.orig/drivers/xen/xen-pciback/conf_space_header.c
+++ 4.0-rc3-xen-pciback/drivers/xen/xen-pciback/conf_space_header.c
@@ -88,9 +88,15 @@ static int command_write(struct pci_dev
printk(KERN_DEBUG DRV_NAME ": %s: set bus master\n",
pci_name(dev));
pci_set_master(dev);
+ } else if (dev->is_busmaster && !is_master_cmd(value)) {
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG DRV_NAME ": %s: clear bus master\n",
+ pci_name(dev));
+ pci_clear_master(dev);
}

- if (value & PCI_COMMAND_INVALIDATE) {
+ if (!(cmd->val & PCI_COMMAND_INVALIDATE) &&
+ (value & PCI_COMMAND_INVALIDATE)) {
if (unlikely(verbose_request))
printk(KERN_DEBUG
DRV_NAME ": %s: enable memory-write-invalidate\n",
@@ -101,6 +107,13 @@ static int command_write(struct pci_dev
pci_name(dev), err);
value &= ~PCI_COMMAND_INVALIDATE;
}
+ } else if ((cmd->val & PCI_COMMAND_INVALIDATE) &&
+ !(value & PCI_COMMAND_INVALIDATE)) {
+ if (unlikely(verbose_request))
+ printk(KERN_DEBUG
+ DRV_NAME ": %s: disable memory-write-invalidate\n",
+ pci_name(dev));
+ pci_clear_mwi(dev);
}

cmd->val = value;



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