2014-02-19 04:53:09

by Jiang Liu

Subject: [PATCH] nouveau, ACPI: fix regression caused by b072e53

On some platforms, ACPI _DSM method (nouveau_op_dsm_muid, function 0)
has special requirements on the fourth parameter, which is different
from ACPI specifications. So revert to the private implementation
to check availability of _DSM functions instead of using common
acpi_check_dsm() interface.

Signed-off-by: Jiang Liu <[email protected]>
---
Hi Maarten,
Thanks for bisecting. Could you please help to verify whether
this patch fixes the regression?

Thanks!
Gerry
---
drivers/gpu/drm/nouveau/nouveau_acpi.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index 4ef83df..c6c7d0d 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -106,6 +106,29 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *
return 0;
}

+/*
+ * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special
+ * requirements on the fourth parameter, so a private implementation
+ * instead of using acpi_check_dsm().
+ */
+static int nouveau_check_optimus_dsm(acpi_handle handle)
+{
+ int result;
+
+ /*
+ * Function 0 returns a Buffer containing available functions.
+ * The args parameter is ignored for function 0, so just put 0 in it
+ */
+ if (nouveau_optimus_dsm(handle, 0, 0, &result)
+ return 0;
+
+ /*
+ * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported.
+ * If the n-th bit is enabled, function n is supported
+ */
+ return result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS);
+}
+
static int nouveau_dsm(acpi_handle handle, int func, int arg)
{
int ret = 0;
@@ -207,8 +230,7 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
1 << NOUVEAU_DSM_POWER))
retval |= NOUVEAU_DSM_HAS_MUX;

- if (acpi_check_dsm(dhandle, nouveau_op_dsm_muid, 0x00000100,
- 1 << NOUVEAU_DSM_OPTIMUS_CAPS))
+ if (nouveau_check_optimus_dsm(dhandle))
retval |= NOUVEAU_DSM_HAS_OPT;

if (retval & NOUVEAU_DSM_HAS_OPT) {
--
1.7.10.4

2014-02-19 09:47:44

by Jiang Liu

Subject: Re: [PATCH] nouveau, ACPI: fix regression caused by b072e53

Hi Maarten,
Forgot to refresh my working tree. Please help to
apply this patch on top of previous one to solve a compilation bug.

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c
b/drivers/gpu/drm/nouveau/no
index c6c7d0d..83face3 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -119,7 +119,7 @@ static int nouveau_check_optimus_dsm(acpi_handle handle)
* Function 0 returns a Buffer containing available functions.
* The args parameter is ignored for function 0, so just put 0 in it
*/
- if (nouveau_optimus_dsm(handle, 0, 0, &result)
+ if (nouveau_optimus_dsm(handle, 0, 0, &result))
return 0;



On 2014/2/19 12:53, Jiang Liu wrote:
> On some platforms, ACPI _DSM method (nouveau_op_dsm_muid, function 0)
> has special requirements on the fourth parameter, which is different
> from ACPI specifications. So revert to the private implementation
> to check availability of _DSM functions instead of using common
> acpi_check_dsm() interface.
>
> Signed-off-by: Jiang Liu <[email protected]>
> ---
> Hi Maarten,
> Thanks for bisecting. Could you please help to verify whether
> this patch fixes the regression?
>
> Thanks!
> Gerry
> ---
> drivers/gpu/drm/nouveau/nouveau_acpi.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> index 4ef83df..c6c7d0d 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> @@ -106,6 +106,29 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *
> return 0;
> }
>
> +/*
> + * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special
> + * requirements on the fourth parameter, so a private implementation
> + * instead of using acpi_check_dsm().
> + */
> +static int nouveau_check_optimus_dsm(acpi_handle handle)
> +{
> + int result;
> +
> + /*
> + * Function 0 returns a Buffer containing available functions.
> + * The args parameter is ignored for function 0, so just put 0 in it
> + */
> + if (nouveau_optimus_dsm(handle, 0, 0, &result)
> + return 0;
> +
> + /*
> + * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported.
> + * If the n-th bit is enabled, function n is supported
> + */
> + return result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS);
> +}
> +
> static int nouveau_dsm(acpi_handle handle, int func, int arg)
> {
> int ret = 0;
> @@ -207,8 +230,7 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
> 1 << NOUVEAU_DSM_POWER))
> retval |= NOUVEAU_DSM_HAS_MUX;
>
> - if (acpi_check_dsm(dhandle, nouveau_op_dsm_muid, 0x00000100,
> - 1 << NOUVEAU_DSM_OPTIMUS_CAPS))
> + if (nouveau_check_optimus_dsm(dhandle))
> retval |= NOUVEAU_DSM_HAS_OPT;
>
> if (retval & NOUVEAU_DSM_HAS_OPT) {
>

2014-02-19 10:12:37

by Maarten Lankhorst

Subject: Re: [PATCH] nouveau, ACPI: fix regression caused by b072e53

op 19-02-14 05:53, Jiang Liu schreef:
> On some platforms, ACPI _DSM method (nouveau_op_dsm_muid, function 0)
> has special requirements on the fourth parameter, which is different
> from ACPI specifications. So revert to the private implementation
> to check availability of _DSM functions instead of using common
> acpi_check_dsm() interface.
>
> Signed-off-by: Jiang Liu <[email protected]>
> ---
> Hi Maarten,
> Thanks for bisecting. Could you please help to verify whether
> this patch fixes the regression?
>
Tested-by: Maarten Lankhorst <[email protected]>

I was wrong about the operator precedence, seems correct after all. :-)

2014-02-19 14:12:15

by Jiang Liu

Subject: Re: [PATCH] nouveau, ACPI: fix regression caused by b072e53

On 2014/2/19 18:12, Maarten Lankhorst wrote:
> op 19-02-14 05:53, Jiang Liu schreef:
>> On some platforms, ACPI _DSM method (nouveau_op_dsm_muid, function 0)
>> has special requirements on the fourth parameter, which is different
>> from ACPI specifications. So revert to the private implementation
>> to check availability of _DSM functions instead of using common
>> acpi_check_dsm() interface.
>>
>> Signed-off-by: Jiang Liu <[email protected]>
>> ---
>> Hi Maarten,
>> Thanks for bisecting. Could you please help to verify whether
>> this patch fixes the regression?
>>
> Tested-by: Maarten Lankhorst <[email protected]>
>
> I was wrong about the operator precedence, seems correct after all. :-)
Hi Maarten,
Thanks for testing.
Cheers!
Gerry