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@xxxxxxxxxxxxxxx> > --- > 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) { > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel