Hello Emil, Thanks for the comments. On 13-05-20, 20:20, Emil Velikov wrote: > Hi Vinod, > > Few high-level comments: > - handful of functions always return 0 and the return value is never > checked - switch to return void Sure makes sense, will do > - annotate all (nearly) arrays as static const Will do > - consistently use multi_reg_write - in some cases non-const array > will be fine, overwriting a few entries as needed Okay that makes sense > - there is very partial comments about the registers/values - missing docs or? yeah am not a big fan either, problem is documentation. Well the spec I have doesn't have register names and few registers are missing :( I have few name created but naming registers turned nasty super quick.. Do let me know if you have suggestions, I will give it one more shot though > Personally I'm in favour of using symbolic names, instead of > hex+comment. Considering how partial the comments are, current > approach is perfectly fine. > > On Wed, 13 May 2020 at 11:06, Vinod Koul <vkoul@xxxxxxxxxx> wrote: > > > > Lontium Lt9611 is a DSI to HDMI bridge which supports two DSI ports and > > I2S port as an input and HDMI port as output > > > > Co-developed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> > > Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> > > > --- /dev/null > > +++ b/drivers/gpu/drm/bridge/lt9611.c > > Please add a vendor prefix to the filename. Okay > > +struct lt9611_mode { > > + u16 hdisplay; > > + u16 vdisplay; > > + u8 fps; > We all enjoy the odd fps game, but let's use vrefresh here. Sure will change > > +static int lt9611_mipi_input_digital(struct lt9611 *lt9611, > > + const struct drm_display_mode *mode) > > +{ > > + regmap_write(lt9611->regmap, 0x8300, LT9611_4LANES); > > + > > + if (mode->hdisplay == 3840) > > + regmap_write(lt9611->regmap, 0x830a, 0x03); > > + else > > + regmap_write(lt9611->regmap, 0x830a, 0x00); > > + > > + regmap_write(lt9611->regmap, 0x824f, 0x80); > > + regmap_write(lt9611->regmap, 0x8250, 0x10); > > + regmap_write(lt9611->regmap, 0x8302, 0x0a); > > + regmap_write(lt9611->regmap, 0x8306, 0x0a); > Create an (non-const) array, overwriting the [1] entry for 3840 mode? So array is the recommendation, I dont have much liking for them but I can see they would be useful here, so will change this and other instances and we can use regmap_multi_reg_write() while taking care of static const for non modified arrays > > > + > > + return 0; > Kill return type. Yup, here and other places > > + regmap_write(lt9611->regmap, 0x82e3, pclk >> 17); /* pclk[19:16] */ > > + regmap_write(lt9611->regmap, 0x82e4, pclk >> 9); /* pclk[15:8] */ > > + regmap_write(lt9611->regmap, 0x82e5, pclk >> 1); /* pclk[7:0] */ > Comment does not match the code. > We're discarding the LSB, so we cannot realistically be writing > pclk[7:0]. Similar applies for the other two. Thanks for pointing, will fix it up > > + /* v_act */ > > + ret = regmap_read(lt9611->regmap, 0x8282, &temp); > > + if (ret) > > + goto end; > > + > > + v_act = temp << 8; > > + ret = regmap_read(lt9611->regmap, 0x8283, &temp); > > + if (ret) > > + goto end; > > + v_act = v_act + temp; > > + > Having a helper for the above "result = read(x) << 8 | read(x+1)" > would be great. > This way one doesn't have to repeat the pattern 4-5 times. will add > > +static int lt9611_read_edid(struct lt9611 *lt9611) > > +{ > > + unsigned int temp; > > + int ret = 0; > > + int i, j; > > + > > + memset(lt9611->edid_buf, 0, EDID_SEG_SIZE); > How about: > memset(lt9611->edid_buf, 0, sizeof(lt9611->edid_buf)); > > Then again, do we need the memset()? We are allocating the memory with > devm_kzalloc() Yes but lt9611_read_edid() is called multiple times so would make sense to memset it, will modify this to sizeof. > > + > > + regmap_write(lt9611->regmap, 0x8503, 0xc9); > > + > > + /* 0xA0 is EDID device address */ > > + regmap_write(lt9611->regmap, 0x8504, 0xa0); > > + /* 0x00 is EDID offset address */ > > + regmap_write(lt9611->regmap, 0x8505, 0x00); > > + /* length for read */ > > + regmap_write(lt9611->regmap, 0x8506, 0x20); > Is this the same 32 as seen in the loops below? #define and use consistently? Sure will use defines here and other places > > + if (block > 1) > > + return -EINVAL; > > + > > + if (block == 0) { > > + /* always read 2 edid blocks once */ > Please mention why that's a good idea. From memory - there aren't many > other drivers that do this. Okay will find the reason for this and > > > + ret = lt9611_read_edid(lt9611); > > + if (ret) { > > + dev_err(lt9611->dev, "edid read failed\n"); > > + return ret; > > + } > > + } > > + > > + if (block % 2 == 0) > > + memcpy(buf, lt9611->edid_buf, len); > > + else > > + memcpy(buf, lt9611->edid_buf + 128, len); > The above can be written as: > memcpy(buf, lt9611->edid_buf + (block * 128), len); correct > > + /* Attach secondary DSI, if specified */ > > + if (lt9611->dsi1_node) { > > + lt9611->dsi1 = lt9611_attach_dsi(lt9611, lt9611->dsi1_node); > > + if (IS_ERR(lt9611->dsi1)) { > > + ret = PTR_ERR(lt9611->dsi1); > > + goto err_unregister_dsi0; > > + } > > + } > > + > > + return 0; > > + > > +err_unregister_dsi0: > Missing detach? If possible directly use lt9611_bridge_detach(). will update > > +static int lt9611_read_device_rev(struct lt9611 *lt9611) > > +{ > > + unsigned int rev; > > + int ret; > > + > > + regmap_write(lt9611->regmap, 0x80ee, 0x01); > > + ret = regmap_read(lt9611->regmap, 0x8002, &rev); > > + if (ret) > > + dev_err(lt9611->dev, "failed to read revision: %d\n", ret); > > + > The "failed" message will be followed by printing random kernel memory. > Initialize rev to some dummy number or omit the dev_info. Am printing the 'ret' error code here and not the uninitialized rev, so I guess this one should be fine > > + ret = lt9611_parse_dt(&client->dev, lt9611); > > + if (ret) { > > + dev_err(dev, "failed to parse device tree\n"); > > + return ret; > > + } > > + > > + ret = lt9611_gpio_init(lt9611); > > + if (ret < 0) > Missing of_node_put() here and for the next few error paths. Yes this should be replaced by jump to of_node_put below > > +static const struct of_device_id lt9611_match_table[] = { > > + {.compatible = "lontium,lt9611"}, > In the above two - add space after { and before }. Pretty sure Correct, will fix this. > ./scripts/checkpatch.pl will complain about those. > Might want to double-check for other issues reported by said tool. Somehow that was not the case :( I always run checkpatch.pl with --strict option. I have 1 warn about 80 char limit for a error message which I have ignored :) -- ~Vinod _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel