* [PATCH] 2.4.18-pre6 AGP enable fixes
@ 2002-01-23 20:46 Bjorn Helgaas
2002-01-27 19:40 ` Alan Cox
0 siblings, 1 reply; 2+ messages in thread
From: Bjorn Helgaas @ 2002-01-23 20:46 UTC (permalink / raw)
To: Alan Cox; +Cc: linux-kernel, dri-devel, Bjorn Helgaas
[-- Attachment #1: Type: text/plain, Size: 2132 bytes --]
In 2.4.17-pre5, agp_generic_agp_enable() and serverworks_agp_enable()
were changed to look for AGP devices as coprocessors on non-VGA
devices as well as VGA devices.
But those functions contain TWO loops that scan for AGP devices (one
to collect the settings they support, and a second to update the
command registers), and 2.4.17-pre5 only changed the first loop in
each case. Shouldn't both loops be changed, as in the "agp_dev" patch
attached?
While looking at this code, I noticed a possible further improvement.
Currently it looks like this:
pci_for_each_dev(device)
{
if((((device->class >> 16) & 0xFF) != PCI_BASE_CLASS_DISPLAY) &&
(device->class != (PCI_CLASS_PROCESSOR_CO << 8)))
continue;
pci_read_config_dword(device, 0x04, &scratch);
if (!(scratch & 0x00100000))
continue;
pci_read_config_byte(device, 0x34, &cap_ptr);
if (cap_ptr != 0x00) {
do {
pci_read_config_dword(device,
cap_ptr, &cap_id);
if ((cap_id & 0xff) != 0x02)
cap_ptr = (cap_id >> 8) & 0xff;
}
while (((cap_id & 0xff) != 0x02) && (cap_ptr != 0x00));
}
if (cap_ptr != 0x00) {
...
The bulk of the above is just a reimplementation of pci_find_capability(),
so what about changing the whole shooting match to the following:
pci_for_each_dev(device) {
cap_ptr = pci_find_capability(device, PCI_CAP_ID_AGP);
if (cap_ptr != 0x00) {
...
Is there anything gained by checking the device class before looking
for the AGP capability? The "agp_find_cap" patch attached implements
this idea. I've compiled and booted kernels with both patches, but
they're otherwise untested.
--
Bjorn Helgaas - bjorn_helgaas@hp.com
Linux Systems Operation R&D
Hewlett-Packard
[-- Attachment #2: agp_dev-2.4.18-pre6.patch --]
[-- Type: text/plain, Size: 1356 bytes --]
diff -u -X /home/helgaas/exclude -r linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c build/linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c
--- linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c Wed Jan 23 10:16:39 2002
+++ build/linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c Wed Jan 23 10:23:23 2002
@@ -506,8 +506,17 @@
* command registers.
*/
- while ((device = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8,
- device)) != NULL) {
+ pci_for_each_dev(device)
+ {
+ /*
+ * Enable AGP devices. Most will be VGA display but
+ * some may be coprocessors on non VGA devices too
+ */
+
+ if((((device->class >> 16) & 0xFF) != PCI_BASE_CLASS_DISPLAY) &&
+ (device->class != (PCI_CLASS_PROCESSOR_CO << 8)))
+ continue;
+
pci_read_config_dword(device, 0x04, &scratch);
if (!(scratch & 0x00100000))
@@ -3421,8 +3430,17 @@
* command registers.
*/
- while ((device = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8,
- device)) != NULL) {
+ pci_for_each_dev(device)
+ {
+ /*
+ * Enable AGP devices. Most will be VGA display but
+ * some may be coprocessors on non VGA devices too
+ */
+
+ if((((device->class >> 16) & 0xFF) != PCI_BASE_CLASS_DISPLAY) &&
+ (device->class != (PCI_CLASS_PROCESSOR_CO << 8)))
+ continue;
+
pci_read_config_dword(device, 0x04, &scratch);
if (!(scratch & 0x00100000))
[-- Attachment #3: agp_find_cap-2.4.18-pre6.patch --]
[-- Type: text/plain, Size: 3866 bytes --]
diff -u -X /home/helgaas/exclude -r linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c build/linux-2.4.18-pre6-find_cap/drivers/char/agp/agpgart_be.c
--- linux-2.4.18-pre6/drivers/char/agp/agpgart_be.c Wed Jan 23 10:16:39 2002
+++ build/linux-2.4.18-pre6-find_cap/drivers/char/agp/agpgart_be.c Wed Jan 23 10:32:12 2002
@@ -410,34 +410,8 @@
*/
- pci_for_each_dev(device)
- {
- /*
- * Enable AGP devices. Most will be VGA display but
- * some may be coprocessors on non VGA devices too
- */
-
- if((((device->class >> 16) & 0xFF) != PCI_BASE_CLASS_DISPLAY) &&
- (device->class != (PCI_CLASS_PROCESSOR_CO << 8)))
- continue;
-
- pci_read_config_dword(device, 0x04, &scratch);
-
- if (!(scratch & 0x00100000))
- continue;
-
- pci_read_config_byte(device, 0x34, &cap_ptr);
-
- if (cap_ptr != 0x00) {
- do {
- pci_read_config_dword(device,
- cap_ptr, &cap_id);
-
- if ((cap_id & 0xff) != 0x02)
- cap_ptr = (cap_id >> 8) & 0xff;
- }
- while (((cap_id & 0xff) != 0x02) && (cap_ptr != 0x00));
- }
+ pci_for_each_dev(device) {
+ cap_ptr = pci_find_capability(device, PCI_CAP_ID_AGP);
if (cap_ptr != 0x00) {
/*
* Ok, here we have a AGP device. Disable impossible
@@ -506,25 +480,8 @@
* command registers.
*/
- while ((device = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8,
- device)) != NULL) {
- pci_read_config_dword(device, 0x04, &scratch);
-
- if (!(scratch & 0x00100000))
- continue;
-
- pci_read_config_byte(device, 0x34, &cap_ptr);
-
- if (cap_ptr != 0x00) {
- do {
- pci_read_config_dword(device,
- cap_ptr, &cap_id);
-
- if ((cap_id & 0xff) != 0x02)
- cap_ptr = (cap_id >> 8) & 0xff;
- }
- while (((cap_id & 0xff) != 0x02) && (cap_ptr != 0x00));
- }
+ pci_for_each_dev(device) {
+ cap_ptr = pci_find_capability(device, PCI_CAP_ID_AGP);
if (cap_ptr != 0x00)
pci_write_config_dword(device, cap_ptr + 8, command);
}
@@ -3326,24 +3283,8 @@
*/
- pci_for_each_dev(device)
- {
- /*
- * Enable AGP devices. Most will be VGA display but
- * some may be coprocessors on non VGA devices too
- */
-
- if((((device->class >> 16) & 0xFF) != PCI_BASE_CLASS_DISPLAY) &&
- (device->class != (PCI_CLASS_PROCESSOR_CO << 8)))
- continue;
-
- pci_read_config_dword(device, 0x04, &scratch);
-
- if (!(scratch & 0x00100000))
- continue;
-
- pci_read_config_byte(device, 0x34, &cap_ptr);
-
+ pci_for_each_dev(device) {
+ cap_ptr = pci_find_capability(device, PCI_CAP_ID_AGP);
if (cap_ptr != 0x00) {
do {
pci_read_config_dword(device,
@@ -3421,25 +3362,8 @@
* command registers.
*/
- while ((device = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8,
- device)) != NULL) {
- pci_read_config_dword(device, 0x04, &scratch);
-
- if (!(scratch & 0x00100000))
- continue;
-
- pci_read_config_byte(device, 0x34, &cap_ptr);
-
- if (cap_ptr != 0x00) {
- do {
- pci_read_config_dword(device,
- cap_ptr, &cap_id);
-
- if ((cap_id & 0xff) != 0x02)
- cap_ptr = (cap_id >> 8) & 0xff;
- }
- while (((cap_id & 0xff) != 0x02) && (cap_ptr != 0x00));
- }
+ pci_for_each_dev(device) {
+ cap_ptr = pci_find_capability(device, PCI_CAP_ID_AGP);
if (cap_ptr != 0x00)
pci_write_config_dword(device, cap_ptr + 8, command);
}
@@ -4037,20 +3961,7 @@
#endif /* CONFIG_AGP_SWORKS */
/* find capndx */
- pci_read_config_dword(dev, 0x04, &scratch);
- if (!(scratch & 0x00100000))
- return -ENODEV;
-
- pci_read_config_byte(dev, 0x34, &cap_ptr);
- if (cap_ptr != 0x00) {
- do {
- pci_read_config_dword(dev, cap_ptr, &cap_id);
-
- if ((cap_id & 0xff) != 0x02)
- cap_ptr = (cap_id >> 8) & 0xff;
- }
- while (((cap_id & 0xff) != 0x02) && (cap_ptr != 0x00));
- }
+ cap_ptr = pci_find_capability(dev, PCI_CAP_ID_AGP);
if (cap_ptr == 0x00)
return -ENODEV;
agp_bridge.capndx = cap_ptr;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] 2.4.18-pre6 AGP enable fixes
2002-01-23 20:46 [PATCH] 2.4.18-pre6 AGP enable fixes Bjorn Helgaas
@ 2002-01-27 19:40 ` Alan Cox
0 siblings, 0 replies; 2+ messages in thread
From: Alan Cox @ 2002-01-27 19:40 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: Alan Cox, linux-kernel, dri-devel, Bjorn Helgaas
> Is there anything gained by checking the device class before looking
> for the AGP capability? The "agp_find_cap" patch attached implements
> this idea. I've compiled and booted kernels with both patches, but
> they're otherwise untested.
Just caution about not twiddling stuff we shouldnt touch.
Alan
^ permalink raw reply [flat|nested] 2+ messages in thread
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