On Wed, Apr 10, 2024 at 06:25:17PM +0300, Ville Syrjälä wrote: > On Wed, Apr 10, 2024 at 12:06:29PM +0300, Tomi Valkeinen wrote: > > On 08/04/2024 20:04, Ville Syrjala wrote: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > __iowmb() isn't available on most architectures. Make > > > its use optional so that the driver can be built on > > > other architectures with COMPILE_TEST=y. > > > > > > Cc: Jyri Sarha <jyri.sarha@xxxxxx> > > > Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/tilcdc/tilcdc_regs.h | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h > > > index f90e2dc3457c..44e4ada30fba 100644 > > > --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h > > > +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h > > > @@ -125,7 +125,9 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data) > > > #if defined(iowrite64) && !defined(iowrite64_is_nonatomic) > > > iowrite64(data, addr); > > > #else > > > +#ifdef __iowmb > > > __iowmb(); > > > +#endif > > > /* This compiles to strd (=64-bit write) on ARM7 */ > > > *(volatile u64 __force *)addr = __cpu_to_le64(data); > > > #endif > > > > As the memory barrier is an important part there, would it be better to > > ifdef based on COMPILE_TEST, to make it clear why it's being done? > > I can do that if you prefer. What if someone tries to actually boot a kernel built with COMPILE_TEST=y on a machine with this hardware? -- Ville Syrjälä Intel
