Re: [PATCH 2/2] via-ide: Fix fuloong2e support

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[Guenter Roeck]

On Fri, Dec 25, 2020 at 12:23:37AM +0100, BALATON Zoltan wrote:
> From: Guenter Roeck <linux@roeck-us.net>
> 
> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
> Add property to via-ide driver to make the mode configurable, and set
> legacy mode for Fuloong2e.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> [balaton: Use bit in flags for property, add comment for missing BAR4]
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  hw/ide/via.c        | 19 +++++++++++++++++--
>  hw/mips/fuloong2e.c |  4 +++-
>  2 files changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/ide/via.c b/hw/ide/via.c
> index be09912b33..7d54d7e829 100644
> --- a/hw/ide/via.c
> +++ b/hw/ide/via.c
> @@ -26,6 +26,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "hw/pci/pci.h"
> +#include "hw/qdev-properties.h"
>  #include "migration/vmstate.h"
>  #include "qemu/module.h"
>  #include "sysemu/dma.h"
> @@ -185,12 +186,19 @@ static void via_ide_realize(PCIDevice *dev, Error **errp)
>                            &d->bus[1], "via-ide1-cmd", 4);
>      pci_register_bar(dev, 3, PCI_BASE_ADDRESS_SPACE_IO, &d->cmd_bar[1]);
>  
> -    bmdma_setup_bar(d);
> -    pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
> +    if (!(d->flags & BIT(PCI_IDE_LEGACY_MODE))) {
> +        /* Missing BAR4 will make Linux driver fall back to legacy PIO mode */
> +        bmdma_setup_bar(d);
> +        pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
> +    }
>  
>      qdev_init_gpio_in(ds, via_ide_set_irq, 2);
>      for (i = 0; i < 2; i++) {
>          ide_bus_new(&d->bus[i], sizeof(d->bus[i]), ds, i, 2);
> +        if (d->flags & BIT(PCI_IDE_LEGACY_MODE)) {
> +            ide_init_ioport(&d->bus[i], NULL, i ? 0x170 : 0x1f0,
> +                            i ? 0x376 : 0x3f6);
> +        }
>          ide_init2(&d->bus[i], qdev_get_gpio_in(ds, i));
>  
>          bmdma_init(&d->bus[i], &d->bmdma[i], d);
> @@ -210,6 +218,12 @@ static void via_ide_exitfn(PCIDevice *dev)
>      }
>  }
>  
> +static Property via_ide_properties[] = {
> +    DEFINE_PROP_BIT("legacy_mode", PCIIDEState, flags, PCI_IDE_LEGACY_MODE,
> +                    false),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static void via_ide_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
> @@ -223,6 +237,7 @@ static void via_ide_class_init(ObjectClass *klass, void *data)
>      k->device_id = PCI_DEVICE_ID_VIA_IDE;
>      k->revision = 0x06;
>      k->class_id = PCI_CLASS_STORAGE_IDE;
> +    device_class_set_props(dc, via_ide_properties);
>      set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
>  }
>  
> diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c
> index 45c596f4fe..f0733e87b7 100644
> --- a/hw/mips/fuloong2e.c
> +++ b/hw/mips/fuloong2e.c
> @@ -253,7 +253,9 @@ static void vt82c686b_southbridge_init(PCIBus *pci_bus, int slot, qemu_irq intc,
>      /* Super I/O */
>      isa_create_simple(isa_bus, TYPE_VT82C686B_SUPERIO);
>  
> -    dev = pci_create_simple(pci_bus, PCI_DEVFN(slot, 1), "via-ide");
> +    dev = pci_new(PCI_DEVFN(slot, 1), "via-ide");
> +    qdev_prop_set_bit(&dev->qdev, "legacy_mode", true);
> +    pci_realize_and_unref(dev, pci_bus, &error_fatal);
>      pci_ide_create_devs(dev);
>  
>      pci_create_simple(pci_bus, PCI_DEVFN(slot, 2), "vt82c686b-usb-uhci");
> -- 
> 2.21.3
> 

[PATCH 0/2] Fix via-ide for fuloong2e

[BALATON Zoltan via]

This implements the legacy-mode emulation option for via-ide which is
needed for Linux on fuloong2e. I've tested that the Debian kernel now
finds CD ROM and MorphOS on pegasos2 is not affected by this.

BALATON Zoltan (1):
  ide: Make room for flags in PCIIDEState and add one for legacy mode

Guenter Roeck (1):
  via-ide: Fix fuloong2e support

 hw/ide/cmd646.c      |  4 ++--
 hw/ide/via.c         | 19 +++++++++++++++++--
 hw/mips/fuloong2e.c  |  4 +++-
 hw/sparc64/sun4u.c   |  2 +-
 include/hw/ide/pci.h |  7 ++++++-
 5 files changed, 29 insertions(+), 7 deletions(-)

-- 
2.21.3

[PATCH 2/2] via-ide: Fix fuloong2e support

[BALATON Zoltan via]

From: Guenter Roeck <linux@roeck-us.net>

Fuloong2e needs to use legacy mode for IDE support to work with Linux.
Add property to via-ide driver to make the mode configurable, and set
legacy mode for Fuloong2e.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[balaton: Use bit in flags for property, add comment for missing BAR4]
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
---
 hw/ide/via.c        | 19 +++++++++++++++++--
 hw/mips/fuloong2e.c |  4 +++-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/hw/ide/via.c b/hw/ide/via.c
index be09912b33..7d54d7e829 100644
--- a/hw/ide/via.c
+++ b/hw/ide/via.c
@@ -26,6 +26,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/pci/pci.h"
+#include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "qemu/module.h"
 #include "sysemu/dma.h"
@@ -185,12 +186,19 @@ static void via_ide_realize(PCIDevice *dev, Error **errp)
                           &d->bus[1], "via-ide1-cmd", 4);
     pci_register_bar(dev, 3, PCI_BASE_ADDRESS_SPACE_IO, &d->cmd_bar[1]);
 
-    bmdma_setup_bar(d);
-    pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
+    if (!(d->flags & BIT(PCI_IDE_LEGACY_MODE))) {
+        /* Missing BAR4 will make Linux driver fall back to legacy PIO mode */
+        bmdma_setup_bar(d);
+        pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
+    }
 
     qdev_init_gpio_in(ds, via_ide_set_irq, 2);
     for (i = 0; i < 2; i++) {
         ide_bus_new(&d->bus[i], sizeof(d->bus[i]), ds, i, 2);
+        if (d->flags & BIT(PCI_IDE_LEGACY_MODE)) {
+            ide_init_ioport(&d->bus[i], NULL, i ? 0x170 : 0x1f0,
+                            i ? 0x376 : 0x3f6);
+        }
         ide_init2(&d->bus[i], qdev_get_gpio_in(ds, i));
 
         bmdma_init(&d->bus[i], &d->bmdma[i], d);
@@ -210,6 +218,12 @@ static void via_ide_exitfn(PCIDevice *dev)
     }
 }
 
+static Property via_ide_properties[] = {
+    DEFINE_PROP_BIT("legacy_mode", PCIIDEState, flags, PCI_IDE_LEGACY_MODE,
+                    false),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void via_ide_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -223,6 +237,7 @@ static void via_ide_class_init(ObjectClass *klass, void *data)
     k->device_id = PCI_DEVICE_ID_VIA_IDE;
     k->revision = 0x06;
     k->class_id = PCI_CLASS_STORAGE_IDE;
+    device_class_set_props(dc, via_ide_properties);
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 }
 
diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c
index 45c596f4fe..f0733e87b7 100644
--- a/hw/mips/fuloong2e.c
+++ b/hw/mips/fuloong2e.c
@@ -253,7 +253,9 @@ static void vt82c686b_southbridge_init(PCIBus *pci_bus, int slot, qemu_irq intc,
     /* Super I/O */
     isa_create_simple(isa_bus, TYPE_VT82C686B_SUPERIO);
 
-    dev = pci_create_simple(pci_bus, PCI_DEVFN(slot, 1), "via-ide");
+    dev = pci_new(PCI_DEVFN(slot, 1), "via-ide");
+    qdev_prop_set_bit(&dev->qdev, "legacy_mode", true);
+    pci_realize_and_unref(dev, pci_bus, &error_fatal);
     pci_ide_create_devs(dev);
 
     pci_create_simple(pci_bus, PCI_DEVFN(slot, 2), "vt82c686b-usb-uhci");
-- 
2.21.3

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[Philippe Mathieu-Daudé]

On 12/25/20 12:23 AM, BALATON Zoltan wrote:
> From: Guenter Roeck <linux@roeck-us.net>
> 
> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
> Add property to via-ide driver to make the mode configurable, and set
> legacy mode for Fuloong2e.
> 

Fixes: 4ea98d317eb ("ide/via: Implement and use native PCI IDE mode")?

> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> [balaton: Use bit in flags for property, add comment for missing BAR4]
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  hw/ide/via.c        | 19 +++++++++++++++++--
>  hw/mips/fuloong2e.c |  4 +++-
>  2 files changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/ide/via.c b/hw/ide/via.c
> index be09912b33..7d54d7e829 100644
> --- a/hw/ide/via.c
> +++ b/hw/ide/via.c
> @@ -26,6 +26,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "hw/pci/pci.h"
> +#include "hw/qdev-properties.h"
>  #include "migration/vmstate.h"
>  #include "qemu/module.h"
>  #include "sysemu/dma.h"
> @@ -185,12 +186,19 @@ static void via_ide_realize(PCIDevice *dev, Error **errp)
>                            &d->bus[1], "via-ide1-cmd", 4);
>      pci_register_bar(dev, 3, PCI_BASE_ADDRESS_SPACE_IO, &d->cmd_bar[1]);
>  
> -    bmdma_setup_bar(d);
> -    pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
> +    if (!(d->flags & BIT(PCI_IDE_LEGACY_MODE))) {
> +        /* Missing BAR4 will make Linux driver fall back to legacy PIO mode */
> +        bmdma_setup_bar(d);
> +        pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
> +    }
>  
>      qdev_init_gpio_in(ds, via_ide_set_irq, 2);
>      for (i = 0; i < 2; i++) {
>          ide_bus_new(&d->bus[i], sizeof(d->bus[i]), ds, i, 2);
> +        if (d->flags & BIT(PCI_IDE_LEGACY_MODE)) {
> +            ide_init_ioport(&d->bus[i], NULL, i ? 0x170 : 0x1f0,
> +                            i ? 0x376 : 0x3f6);
> +        }
>          ide_init2(&d->bus[i], qdev_get_gpio_in(ds, i));
>  
>          bmdma_init(&d->bus[i], &d->bmdma[i], d);
> @@ -210,6 +218,12 @@ static void via_ide_exitfn(PCIDevice *dev)
>      }
>  }
>  
> +static Property via_ide_properties[] = {
> +    DEFINE_PROP_BIT("legacy_mode", PCIIDEState, flags, PCI_IDE_LEGACY_MODE,
> +                    false),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static void via_ide_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
> @@ -223,6 +237,7 @@ static void via_ide_class_init(ObjectClass *klass, void *data)
>      k->device_id = PCI_DEVICE_ID_VIA_IDE;
>      k->revision = 0x06;
>      k->class_id = PCI_CLASS_STORAGE_IDE;
> +    device_class_set_props(dc, via_ide_properties);
>      set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
>  }
>  
> diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c
> index 45c596f4fe..f0733e87b7 100644
> --- a/hw/mips/fuloong2e.c
> +++ b/hw/mips/fuloong2e.c
> @@ -253,7 +253,9 @@ static void vt82c686b_southbridge_init(PCIBus *pci_bus, int slot, qemu_irq intc,
>      /* Super I/O */
>      isa_create_simple(isa_bus, TYPE_VT82C686B_SUPERIO);
>  
> -    dev = pci_create_simple(pci_bus, PCI_DEVFN(slot, 1), "via-ide");
> +    dev = pci_new(PCI_DEVFN(slot, 1), "via-ide");
> +    qdev_prop_set_bit(&dev->qdev, "legacy_mode", true);
> +    pci_realize_and_unref(dev, pci_bus, &error_fatal);
>      pci_ide_create_devs(dev);
>  
>      pci_create_simple(pci_bus, PCI_DEVFN(slot, 2), "vt82c686b-usb-uhci");
> 

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[BALATON Zoltan via]

[-- Attachment #1: Type: text/plain, Size: 4145 bytes --]

On Sun, 27 Dec 2020, Philippe Mathieu-Daudé wrote:
> On 12/25/20 12:23 AM, BALATON Zoltan wrote:
>> From: Guenter Roeck <linux@roeck-us.net>
>>
>> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
>> Add property to via-ide driver to make the mode configurable, and set
>> legacy mode for Fuloong2e.
>>
>
> Fixes: 4ea98d317eb ("ide/via: Implement and use native PCI IDE mode")?

Not really. That patch did what it said (only emulating (half) native mode 
instead of only emulating legacy mode) so it wasn't broken per se but it 
turned out that approach wasn't good enough for all use cases so this now 
takes a different turn (emulating either legacy or half-native mode based 
on option property). Therefore. I don't think Fixes: applies in this case. 
It fixes an issue with a guest but replaces previous patch with different 
approach. (Even though it reuses most of it.)

Regards,
BALATON Zoltan

>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> [balaton: Use bit in flags for property, add comment for missing BAR4]
>> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
>> ---
>>  hw/ide/via.c        | 19 +++++++++++++++++--
>>  hw/mips/fuloong2e.c |  4 +++-
>>  2 files changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/ide/via.c b/hw/ide/via.c
>> index be09912b33..7d54d7e829 100644
>> --- a/hw/ide/via.c
>> +++ b/hw/ide/via.c
>> @@ -26,6 +26,7 @@
>>
>>  #include "qemu/osdep.h"
>>  #include "hw/pci/pci.h"
>> +#include "hw/qdev-properties.h"
>>  #include "migration/vmstate.h"
>>  #include "qemu/module.h"
>>  #include "sysemu/dma.h"
>> @@ -185,12 +186,19 @@ static void via_ide_realize(PCIDevice *dev, Error **errp)
>>                            &d->bus[1], "via-ide1-cmd", 4);
>>      pci_register_bar(dev, 3, PCI_BASE_ADDRESS_SPACE_IO, &d->cmd_bar[1]);
>>
>> -    bmdma_setup_bar(d);
>> -    pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
>> +    if (!(d->flags & BIT(PCI_IDE_LEGACY_MODE))) {
>> +        /* Missing BAR4 will make Linux driver fall back to legacy PIO mode */
>> +        bmdma_setup_bar(d);
>> +        pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
>> +    }
>>
>>      qdev_init_gpio_in(ds, via_ide_set_irq, 2);
>>      for (i = 0; i < 2; i++) {
>>          ide_bus_new(&d->bus[i], sizeof(d->bus[i]), ds, i, 2);
>> +        if (d->flags & BIT(PCI_IDE_LEGACY_MODE)) {
>> +            ide_init_ioport(&d->bus[i], NULL, i ? 0x170 : 0x1f0,
>> +                            i ? 0x376 : 0x3f6);
>> +        }
>>          ide_init2(&d->bus[i], qdev_get_gpio_in(ds, i));
>>
>>          bmdma_init(&d->bus[i], &d->bmdma[i], d);
>> @@ -210,6 +218,12 @@ static void via_ide_exitfn(PCIDevice *dev)
>>      }
>>  }
>>
>> +static Property via_ide_properties[] = {
>> +    DEFINE_PROP_BIT("legacy_mode", PCIIDEState, flags, PCI_IDE_LEGACY_MODE,
>> +                    false),
>> +    DEFINE_PROP_END_OF_LIST(),
>> +};
>> +
>>  static void via_ide_class_init(ObjectClass *klass, void *data)
>>  {
>>      DeviceClass *dc = DEVICE_CLASS(klass);
>> @@ -223,6 +237,7 @@ static void via_ide_class_init(ObjectClass *klass, void *data)
>>      k->device_id = PCI_DEVICE_ID_VIA_IDE;
>>      k->revision = 0x06;
>>      k->class_id = PCI_CLASS_STORAGE_IDE;
>> +    device_class_set_props(dc, via_ide_properties);
>>      set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
>>  }
>>
>> diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c
>> index 45c596f4fe..f0733e87b7 100644
>> --- a/hw/mips/fuloong2e.c
>> +++ b/hw/mips/fuloong2e.c
>> @@ -253,7 +253,9 @@ static void vt82c686b_southbridge_init(PCIBus *pci_bus, int slot, qemu_irq intc,
>>      /* Super I/O */
>>      isa_create_simple(isa_bus, TYPE_VT82C686B_SUPERIO);
>>
>> -    dev = pci_create_simple(pci_bus, PCI_DEVFN(slot, 1), "via-ide");
>> +    dev = pci_new(PCI_DEVFN(slot, 1), "via-ide");
>> +    qdev_prop_set_bit(&dev->qdev, "legacy_mode", true);
>> +    pci_realize_and_unref(dev, pci_bus, &error_fatal);
>>      pci_ide_create_devs(dev);
>>
>>      pci_create_simple(pci_bus, PCI_DEVFN(slot, 2), "vt82c686b-usb-uhci");
>>
>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
>

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[Philippe Mathieu-Daudé]

On 12/27/20 5:40 PM, BALATON Zoltan via wrote:
> On Sun, 27 Dec 2020, Philippe Mathieu-Daudé wrote:
>> On 12/25/20 12:23 AM, BALATON Zoltan wrote:
>>> From: Guenter Roeck <linux@roeck-us.net>
>>>
>>> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
>>> Add property to via-ide driver to make the mode configurable, and set
>>> legacy mode for Fuloong2e.
>>>
>>
>> Fixes: 4ea98d317eb ("ide/via: Implement and use native PCI IDE mode")?
> 
> Not really. That patch did what it said (only emulating (half) native
> mode instead of only emulating legacy mode) so it wasn't broken per se
> but it turned out that approach wasn't good enough for all use cases so
> this now takes a different turn (emulating either legacy or half-native
> mode based on option property). Therefore. I don't think Fixes: applies
> in this case. It fixes an issue with a guest but replaces previous patch
> with different approach. (Even though it reuses most of it.)

Well, if Linux guest got broken by this commit, why not name it a "fix"?
Anyway I don't mind how it is called. I find important to refer to the
commit hash to help navigating between commits while reviewing history.

What about:

'''
The legacy mode for IDE support has been removed in commit 4ea98d317eb
("ide/via: Implement and use native PCI IDE mode"). When using a Linux
guest, the Fuloong2e machine requires the legacy mode.
Add property to via-ide driver to make the mode configurable, and set
legacy mode for Fuloong2e.
'''

Guenter, is that OK with you? (I can update when applying this series
via the MIPS tree).

Thanks,

Phil.

> 
> Regards,
> BALATON Zoltan

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[Guenter Roeck]

On 12/27/20 9:24 AM, Philippe Mathieu-Daudé wrote:
> On 12/27/20 5:40 PM, BALATON Zoltan via wrote:
>> On Sun, 27 Dec 2020, Philippe Mathieu-Daudé wrote:
>>> On 12/25/20 12:23 AM, BALATON Zoltan wrote:
>>>> From: Guenter Roeck <linux@roeck-us.net>
>>>>
>>>> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
>>>> Add property to via-ide driver to make the mode configurable, and set
>>>> legacy mode for Fuloong2e.
>>>>
>>>
>>> Fixes: 4ea98d317eb ("ide/via: Implement and use native PCI IDE mode")?
>>
>> Not really. That patch did what it said (only emulating (half) native
>> mode instead of only emulating legacy mode) so it wasn't broken per se
>> but it turned out that approach wasn't good enough for all use cases so
>> this now takes a different turn (emulating either legacy or half-native
>> mode based on option property). Therefore. I don't think Fixes: applies
>> in this case. It fixes an issue with a guest but replaces previous patch
>> with different approach. (Even though it reuses most of it.)
> 
> Well, if Linux guest got broken by this commit, why not name it a "fix"?
> Anyway I don't mind how it is called. I find important to refer to the
> commit hash to help navigating between commits while reviewing history.
> 
> What about:
> 
> '''
> The legacy mode for IDE support has been removed in commit 4ea98d317eb
> ("ide/via: Implement and use native PCI IDE mode"). When using a Linux
> guest, the Fuloong2e machine requires the legacy mode.
> Add property to via-ide driver to make the mode configurable, and set
> legacy mode for Fuloong2e.
> '''
> 
> Guenter, is that OK with you? (I can update when applying this series
> via the MIPS tree).
> 

Sure, I don't really care about the commit message as long as the problem
is fixed.

Guenter

Re: [PATCH 2/2] via-ide: Fix fuloong2e support

[BALATON Zoltan via]

[-- Attachment #1: Type: text/plain, Size: 2034 bytes --]

On Sun, 27 Dec 2020, Philippe Mathieu-Daudé wrote:
> On 12/27/20 5:40 PM, BALATON Zoltan via wrote:
>> On Sun, 27 Dec 2020, Philippe Mathieu-Daudé wrote:
>>> On 12/25/20 12:23 AM, BALATON Zoltan wrote:
>>>> From: Guenter Roeck <linux@roeck-us.net>
>>>>
>>>> Fuloong2e needs to use legacy mode for IDE support to work with Linux.
>>>> Add property to via-ide driver to make the mode configurable, and set
>>>> legacy mode for Fuloong2e.
>>>>
>>>
>>> Fixes: 4ea98d317eb ("ide/via: Implement and use native PCI IDE mode")?
>>
>> Not really. That patch did what it said (only emulating (half) native
>> mode instead of only emulating legacy mode) so it wasn't broken per se
>> but it turned out that approach wasn't good enough for all use cases so
>> this now takes a different turn (emulating either legacy or half-native
>> mode based on option property). Therefore. I don't think Fixes: applies
>> in this case. It fixes an issue with a guest but replaces previous patch
>> with different approach. (Even though it reuses most of it.)
>
> Well, if Linux guest got broken by this commit, why not name it a "fix"?

We do call it a fix in the patch title. I just thought Fixes: tag was more 
for either security fixes or cases when original commit had a bug that's 
fixed up by this patch which is not exactly the case here.

> Anyway I don't mind how it is called. I find important to refer to the
> commit hash to help navigating between commits while reviewing history.
>
> What about:
>
> '''
> The legacy mode for IDE support has been removed in commit 4ea98d317eb
> ("ide/via: Implement and use native PCI IDE mode"). When using a Linux
> guest, the Fuloong2e machine requires the legacy mode.
> Add property to via-ide driver to make the mode configurable, and set
> legacy mode for Fuloong2e.
> '''
>
> Guenter, is that OK with you? (I can update when applying this series
> via the MIPS tree).

I've submitted v2 with this commit message (slightly edited) mentioning 
the original commit for tracking.

Regards,
BALATON Zoltan