Hi Thierry, On Mon, 2016-05-30 at 12:41 +0200, Thierry Reding wrote: > On Fri, May 20, 2016 at 11:05:32PM +0800, yt.shen@xxxxxxxxxxxx wrote: > > From: YT Shen <yt.shen@xxxxxxxxxxxx> > > > > Add MT8173 suffix for hardware related macros. > > > > Signed-off-by: YT Shen <yt.shen@xxxxxxxxxxxx> > > --- > > drivers/gpu/drm/mediatek/mtk_drm_ddp.c | 62 ++++++++++++++++---------------- > > 1 file changed, 31 insertions(+), 31 deletions(-) > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp.c > > index 17ba935..d6aafd4 100644 > > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp.c > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp.c > > @@ -36,21 +36,21 @@ > > #define DISP_REG_MUTEX_MOD(n) (0x2c + 0x20 * (n)) > > #define DISP_REG_MUTEX_SOF(n) (0x30 + 0x20 * (n)) > > > > -#define MUTEX_MOD_DISP_OVL0 BIT(11) > > -#define MUTEX_MOD_DISP_OVL1 BIT(12) > > -#define MUTEX_MOD_DISP_RDMA0 BIT(13) > > -#define MUTEX_MOD_DISP_RDMA1 BIT(14) > > -#define MUTEX_MOD_DISP_RDMA2 BIT(15) > > -#define MUTEX_MOD_DISP_WDMA0 BIT(16) > > -#define MUTEX_MOD_DISP_WDMA1 BIT(17) > > -#define MUTEX_MOD_DISP_COLOR0 BIT(18) > > -#define MUTEX_MOD_DISP_COLOR1 BIT(19) > > -#define MUTEX_MOD_DISP_AAL BIT(20) > > -#define MUTEX_MOD_DISP_GAMMA BIT(21) > > -#define MUTEX_MOD_DISP_UFOE BIT(22) > > -#define MUTEX_MOD_DISP_PWM0 BIT(23) > > -#define MUTEX_MOD_DISP_PWM1 BIT(24) > > -#define MUTEX_MOD_DISP_OD BIT(25) > > +#define MUTEX_MOD_DISP_OVL0_MT8173 BIT(11) > > +#define MUTEX_MOD_DISP_OVL1_MT8173 BIT(12) > > +#define MUTEX_MOD_DISP_RDMA0_MT8173 BIT(13) > > +#define MUTEX_MOD_DISP_RDMA1_MT8173 BIT(14) > > +#define MUTEX_MOD_DISP_RDMA2_MT8173 BIT(15) > > +#define MUTEX_MOD_DISP_WDMA0_MT8173 BIT(16) > > +#define MUTEX_MOD_DISP_WDMA1_MT8173 BIT(17) > > +#define MUTEX_MOD_DISP_COLOR0_MT8173 BIT(18) > > +#define MUTEX_MOD_DISP_COLOR1_MT8173 BIT(19) > > +#define MUTEX_MOD_DISP_AAL_MT8173 BIT(20) > > +#define MUTEX_MOD_DISP_GAMMA_MT8173 BIT(21) > > +#define MUTEX_MOD_DISP_UFOE_MT8173 BIT(22) > > +#define MUTEX_MOD_DISP_PWM0_MT8173 BIT(23) > > +#define MUTEX_MOD_DISP_PWM1_MT8173 BIT(24) > > +#define MUTEX_MOD_DISP_OD_MT8173 BIT(25) > > Just a random fly-by comment: this looks like a hardware spinlock, have > you ever considered implementing this as a hwspinlock driver? See the > drivers/hwspinlock subdirectory for existing examples. > > Thierry I see the drivers/hwspinlock and Documentation/hwspinlock.txt Yes, we can implement this like a hardware spinlock. But I have some questions, the document says: "Hardware spinlock modules provide hardware assistance for synchronization and mutual exclusion between heterogeneous processors and those not operating under a single, shared operating system" The mutex here is a handshake interface between software and hardware. The hardware is the display controller, the software is the drm display driver, and no other consumers need to access this mutex. So I think that using hwspinlock to implement a bit too complicated, am I right? I will use iopoll macros to implement this part in the next version. Thanks. yt.shen -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
