On Tue, Jun 25, 2024 at 08:33:48AM GMT, Keith Zhao wrote: > > > > -----Original Message----- > > From: Dmitry Baryshkov <dmitry.barysh...@linaro.org> > > Sent: 2024年6月24日 5:11 > > To: Keith Zhao <keith.z...@starfivetech.com> > > Cc: andrzej.ha...@intel.com; neil.armstr...@linaro.org; rf...@kernel.org; > > laurent.pinch...@ideasonboard.com; jo...@kwiboo.se; > > jernej.skra...@gmail.com; maarten.lankho...@linux.intel.com; > > mrip...@kernel.org; tzimmerm...@suse.de; airl...@gmail.com; > > dan...@ffwll.ch; r...@kernel.org; krzk...@kernel.org; conor...@kernel.org; > > h...@rock-chips.com; he...@sntech.de; andy....@rock-chips.com; Xingyu Wu > > <xingyu...@starfivetech.com>; p.za...@pengutronix.de; Jack Zhu > > <jack....@starfivetech.com>; Shengyang Chen > > <shengyang.c...@starfivetech.com>; dri-devel@lists.freedesktop.org; > > devicet...@vger.kernel.org; linux-ker...@vger.kernel.org; > > linux-arm-ker...@lists.infradead.org > > Subject: Re: [PATCH v4 10/10] drm/vs: add simple dsi encoder > > > > On Sun, Jun 23, 2024 at 07:17:09AM GMT, Keith Zhao wrote: > > > Hi Dmitry: > > > > > > > On Tue, May 21, 2024 at 06:58:17PM +0800, keith wrote: > > > > > > > + > > > > > "starfive,syscon", > > > > > + 2, > > > > > args); > > > > > + > > > > > + if (IS_ERR(simple->dss_regmap)) { > > > > > + return dev_err_probe(dev, PTR_ERR(simple->dss_regmap), > > > > > + "getting the regmap failed\n"); > > > > > + } > > > > > + > > > > > + simple->offset = args[0]; > > > > > + simple->mask = args[1]; > > > > > > > > Is the value that you've read platform dependent or use case dependent? > > > > What is the actual value being written? Why are you using syscon for it? > > > > > > The syscon is used to select crtcs binded with encoder, If this > > > encoder binds to crtc0 , set the syscon reg bit0 = 1 If this encoder > > > binds to crtc1 , set the syscon reg bit1 = 1 (0x2) Maybe I can do this > > > by the possible_crtc instead of using args from dts > > > > If this is a constant between your platforms, it should not be a part of DT. > > > > > > > > > > > > > > > > > + > > > > > + return 0; > > > > > +} > > > > > + > > > > > +static void vs_encoder_atomic_enable(struct drm_encoder *encoder, > > > > > +struct drm_atomic_state *state) { > > > > > + struct vs_simple_encoder *simple = to_simple_encoder(encoder); > > > > > + > > > > > + regmap_update_bits(simple->dss_regmap, simple->offset, > > > > > +simple->mask, > > > > > +simple->mask); > > > > > > > > > > > > A purist in me would ask to have separate mask and value to write. > > > Understand , will avoid this action > > > > > > > > > +} > > > > > > > > Is it necessary to clear those bits when stopping the stream? > > > No need to do this , if clear those bits , the encoder will point to a > > > unknown crtc > > > > what are the consequences? Is it desirable or not? > There are two crtcs. > Each display terminal encoder can combine any crtc, depending on the value of > possible crtc. > When the bit is 0, it means that the encoder matches crtc0. > When the bit is 1, it means that the encoder matches crtc1. > The possible crtc of this encoder is 2 , the reg bit is 1. > When the video stream is stopped, if the bit is cleared, the result is that > the encoder hardware points to crtc0, > and the encoder points to crtc1 based on the drm framework(because the > possible crtc no change).
I'm not sure if I understood you correctly. If it doesn't disable or disconnect the encoder, I'd skip that in the .disable path. -- With best wishes Dmitry