From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Kocialkowski Subject: Re: [PATCH v2 34/43] drm/sun4i: Add buffer stride and offset configuration for tiling mode Date: Tue, 04 Dec 2018 14:30:59 +0100 Message-ID: <673fa8ed8e43943c29f050fd21954e77789134c3.camel@bootlin.com> References: <20181123092515.2511-1-paul.kocialkowski@bootlin.com> <20181123092515.2511-35-paul.kocialkowski@bootlin.com> <20181127092428.z7p4mxnf3jxuqcv7@flea> Reply-To: paul.kocialkowski-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <20181127092428.z7p4mxnf3jxuqcv7@flea> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Maarten Lankhorst , Sean Paul , David Airlie , Chen-Yu Tsai , Thomas Petazzoni , linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Daniel Vetter List-Id: dri-devel@lists.freedesktop.org Hi, On Tue, 2018-11-27 at 10:24 +0100, Maxime Ripard wrote: > On Fri, Nov 23, 2018 at 10:25:06AM +0100, Paul Kocialkowski wrote: > > This introduces stride and offset configuration for the VPU tiling mode. > > Stride is calculated differently than it is for linear formats and an > > offset is calculated, for which new register definitions are introduced. > > > > Signed-off-by: Paul Kocialkowski > > --- > > drivers/gpu/drm/sun4i/sun4i_frontend.c | 54 ++++++++++++++++++++++++-- > > drivers/gpu/drm/sun4i/sun4i_frontend.h | 7 ++++ > > 2 files changed, 58 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.c b/drivers/gpu/drm/sun4i/sun4i_frontend.c > > index efa1ff0802bd..3f76a5572449 100644 > > --- a/drivers/gpu/drm/sun4i/sun4i_frontend.c > > +++ b/drivers/gpu/drm/sun4i/sun4i_frontend.c > > @@ -125,21 +125,69 @@ void sun4i_frontend_update_buffer(struct sun4i_frontend *frontend, > > { > > struct drm_plane_state *state = plane->state; > > struct drm_framebuffer *fb = state->fb; > > + unsigned int strides[3] = {}; > > + > > dma_addr_t paddr; > > bool swap; > > > > + if (fb->modifier == DRM_FORMAT_MOD_ALLWINNER_TILED) { > > + unsigned int width = state->src_w >> 16; > > + unsigned int offset; > > + > > + /* > > + * In MB32 tiled mode, the stride is defined as the distance > > + * between the start of the end line of the current tile and > > + * the start of the first line in the next vertical tile. > > + * > > + * Tiles are represented in row-major order, thus the end line > > + * of current tile starts at: 31 * 32 (31 lines of 32 cols), > > + * the next vertical tile starts at: 32-bit-aligned-width * 32 > > + * and the distance is: 32 * (32-bit-aligned-width - 31). > > + */ > > + > > + strides[0] = (fb->pitches[0] - 31) * 32; > > + > > + /* Offset of the bottom-right point in the end tile. */ > > + offset = (width + (32 - 1)) & (32 - 1); > > Those computations are a bit obscure. I guess adding a bunch of > defines, and using the round_up / _down and ALIGN macros would help Fair enough, I will add a more explicit comment and a macro in v3. > > + regmap_write(frontend->regs, SUN4I_FRONTEND_TB_OFF0_REG, > > + SUN4I_FRONTEND_TB_OFF_X1(offset)); > > + > > + if (fb->format->num_planes > 1) { > > + strides[1] = (fb->pitches[1] - 31) * 32; > > + > > + regmap_write(frontend->regs, SUN4I_FRONTEND_TB_OFF1_REG, > > + SUN4I_FRONTEND_TB_OFF_X1(offset)); > > + } > > + > > + if (fb->format->num_planes > 2) { > > + strides[2] = (fb->pitches[2] - 31) * 32; > > + > > + regmap_write(frontend->regs, SUN4I_FRONTEND_TB_OFF2_REG, > > + SUN4I_FRONTEND_TB_OFF_X1(offset)); > > + } > > I guess we could fall in a situation where this is not cleared when > moving from a format with 3 planes to one with 2 for example. Would > that break anything? I have tested this case and nothing breaks so we're good! Cheers, Paul -- Paul Kocialkowski, Bootlin (formerly Free Electrons) Embedded Linux and kernel engineering https://bootlin.com