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 jiang.liu@linux.intel.com

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) {