2023-04-20 08:25:45

by Jammy Huang

[permalink] [raw]

Subject: [PATCH v2] drm/ast: Fix ARM compatibility

---

ARM architecture only has 'memory', so all devices are accessed by
MMIO if possible.

Signed-off-by: Jammy Huang <[email protected]>
---
v2 changes:
- Use MMIO after AST2500 which enable MMIO by default.
---
drivers/gpu/drm/ast/ast_main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index f83ce77127cb..d384e810fa4d 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -425,11 +425,12 @@ struct ast_private *ast_device_create(const struct drm_driver *drv,
return ERR_PTR(-EIO);

/*
- * If we don't have IO space at all, use MMIO now and
- * assume the chip has MMIO enabled by default (rev 0x20
- * and higher).
+ * After AST2500, MMIO is enabled by default, and it should be adapted
+ * to be compatible with Arm.
*/
- if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
+ if (pdev->revision >= 0x40) {
+ ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
+ } else if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
drm_info(dev, "platform has no IO space, trying MMIO\n");
ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
}

base-commit: e62252bc55b6d4eddc6c2bdbf95a448180d6a08d
--
2.25.1

2023-04-20 09:09:37

by Thomas Zimmermann

[permalink] [raw]

Subject: Re: [PATCH v2] drm/ast: Fix ARM compatibility

---

Hi

Am 20.04.23 um 10:09 schrieb Jammy Huang:
> ARM architecture only has 'memory', so all devices are accessed by
> MMIO if possible.
>
> Signed-off-by: Jammy Huang <[email protected]>
> ---
> v2 changes:
> - Use MMIO after AST2500 which enable MMIO by default.
> ---
> drivers/gpu/drm/ast/ast_main.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
> index f83ce77127cb..d384e810fa4d 100644
> --- a/drivers/gpu/drm/ast/ast_main.c
> +++ b/drivers/gpu/drm/ast/ast_main.c
> @@ -425,11 +425,12 @@ struct ast_private *ast_device_create(const struct drm_driver *drv,
> return ERR_PTR(-EIO);
>
> /*
> - * If we don't have IO space at all, use MMIO now and
> - * assume the chip has MMIO enabled by default (rev 0x20
> - * and higher).
> + * After AST2500, MMIO is enabled by default, and it should be adapted

By 'adapted', you mean 'adopted'?

Apart from that:

Reviewed-by: Thomas Zimmermann <[email protected]>

I also ran this patch on an AST2100, which still works as before.

Best regards
Thomas

> + * to be compatible with Arm.
> */
> - if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
> + if (pdev->revision >= 0x40) {
> + ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
> + } else if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
> drm_info(dev, "platform has no IO space, trying MMIO\n");
> ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
> }
>
> base-commit: e62252bc55b6d4eddc6c2bdbf95a448180d6a08d

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

---

Attachments:

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2023-04-20 09:41:22

by Jammy Huang

[permalink] [raw]

Subject: Re: [PATCH v2] drm/ast: Fix ARM compatibility

---

Hi Thomas,

Thanks for help. I will update a new patch per your comments

On 2023/4/20 下午 04:57, Thomas Zimmermann wrote:
> Hi
>
> Am 20.04.23 um 10:09 schrieb Jammy Huang:
>> ARM architecture only has 'memory', so all devices are accessed by
>> MMIO if possible.
>>
>> Signed-off-by: Jammy Huang <[email protected]>
>> ---
>>   v2 changes:
>>    - Use MMIO after AST2500 which enable MMIO by default.
>> ---
>>   drivers/gpu/drm/ast/ast_main.c | 9 +++++----
>>   1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ast/ast_main.c
>> b/drivers/gpu/drm/ast/ast_main.c
>> index f83ce77127cb..d384e810fa4d 100644
>> --- a/drivers/gpu/drm/ast/ast_main.c
>> +++ b/drivers/gpu/drm/ast/ast_main.c
>> @@ -425,11 +425,12 @@ struct ast_private *ast_device_create(const
>> struct drm_driver *drv,
>>           return ERR_PTR(-EIO);
>>         /*
>> -     * If we don't have IO space at all, use MMIO now and
>> -     * assume the chip has MMIO enabled by default (rev 0x20
>> -     * and higher).
>> +     * After AST2500, MMIO is enabled by default, and it should be
>> adapted
>
> By 'adapted', you mean 'adopted'?
>
> Apart from that:
>
> Reviewed-by: Thomas Zimmermann <[email protected]>
>
> I also ran this patch on an AST2100, which still works as before.
>
> Best regards
> Thomas
>
>> +     * to be compatible with Arm.
>>        */
>> -    if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
>> +    if (pdev->revision >= 0x40) {
>> +        ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
>> +    } else if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) {
>>           drm_info(dev, "platform has no IO space, trying MMIO\n");
>>           ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
>>       }
>>
>> base-commit: e62252bc55b6d4eddc6c2bdbf95a448180d6a08d
>
--
Best Regards
Jammy