Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932178AbcJZJIX (ORCPT ); Wed, 26 Oct 2016 05:08:23 -0400 Received: from mailgw02.mediatek.com ([218.249.47.111]:59711 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754939AbcJZJHW (ORCPT ); Wed, 26 Oct 2016 05:07:22 -0400 Message-ID: <1477472832.7427.1.camel@mszsdhlt06> Subject: Re: [PATCH v2] drm/mediatek: fixed the calc method of data rate per lane From: Jitao Shi To: CK Hu CC: Philipp Zabel , Matthias Brugger , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "Ajay Kumar" , Inki Dae , "Rahul Sharma" , Sean Paul , Vincent Palatin , Andy Yan , Russell King , , , , , , , "Sascha Hauer" , , , , , Date: Wed, 26 Oct 2016 17:07:12 +0800 In-Reply-To: <1477464081.17405.2.camel@mtksdaap41> References: <1477374045-2837-1-git-send-email-jitao.shi@mediatek.com> <1477464081.17405.2.camel@mtksdaap41> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5529 Lines: 152 On Wed, 2016-10-26 at 14:41 +0800, CK Hu wrote: > Hi, Jitao: > > On Tue, 2016-10-25 at 13:40 +0800, Jitao Shi wrote: > > Tune dsi frame rate by pixel clock, dsi add some extra signal (i.e. Tlpx, > > Ths-prepare, Ths-zero, Ths-trail,Ths-exit) when enter and exit LP mode, this > > signal will cause h-time larger than normal and reduce FPS. > > Need to multiply a coefficient to offset the extra signal's effect. > > coefficient = ((htotal*bpp/lane_number)+Tlpx+Ths_prep+Ths_zero+Ths_trail+ > > Ths_exit)/(htotal*bpp/lane_number)) > > > > Signed-off-by: Jitao Shi > > --- > > Change since v1: > > - phy_timing2 and phy_timing3 refer clock cycle time. > > - define values of LPX HS_PRPR HS_ZERO HS_TRAIL TA_GO TA_SURE TA_GET DA_HS_EXIT > > --- > > drivers/gpu/drm/mediatek/mtk_dsi.c | 103 +++++++++++++++++++++++------------- > > 1 file changed, 67 insertions(+), 36 deletions(-) > > > > [snip...] > > > > > -static void dsi_phy_timconfig(struct mtk_dsi *dsi) > > +static void dsi_phy_timconfig(struct mtk_dsi *dsi, u32 phy_timing0, > > + u32 phy_timing1, u32 phy_timing2, > > + u32 phy_timing3) > > { > > - u32 timcon0, timcon1, timcon2, timcon3; > > - unsigned int ui, cycle_time; > > - unsigned int lpx; > > - > > - ui = 1000 / dsi->data_rate + 0x01; > > - cycle_time = 8000 / dsi->data_rate + 0x01; > > - lpx = 5; > > - > > - timcon0 = (8 << 24) | (0xa << 16) | (0x6 << 8) | lpx; > > - timcon1 = (7 << 24) | (5 * lpx << 16) | ((3 * lpx) / 2) << 8 | > > - (4 * lpx); > > - timcon2 = ((NS_TO_CYCLE(0x64, cycle_time) + 0xa) << 24) | > > - (NS_TO_CYCLE(0x150, cycle_time) << 16); > > - timcon3 = (2 * lpx) << 16 | NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8 | > > - NS_TO_CYCLE(0x40, cycle_time); > > - > > - writel(timcon0, dsi->regs + DSI_PHY_TIMECON0); > > - writel(timcon1, dsi->regs + DSI_PHY_TIMECON1); > > - writel(timcon2, dsi->regs + DSI_PHY_TIMECON2); > > - writel(timcon3, dsi->regs + DSI_PHY_TIMECON3); > > Why do you move these calculation to mtk_dsi_poweron()? You can keep > calculation here and just do some modification. > > Regards, > CK Thanks for your review. I'll fix it in next patchset. Best Regards jitao > > > + writel(phy_timing0, dsi->regs + DSI_PHY_TIMECON0); > > + writel(phy_timing1, dsi->regs + DSI_PHY_TIMECON1); > > + writel(phy_timing2, dsi->regs + DSI_PHY_TIMECON2); > > + writel(phy_timing3, dsi->regs + DSI_PHY_TIMECON3); > > } > > > > static void mtk_dsi_enable(struct mtk_dsi *dsi) > > @@ -202,19 +188,51 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) > > { > > struct device *dev = dsi->dev; > > int ret; > > + u64 bit_clock, total_bits; > > + u32 htotal, htotal_bits, bit_per_pixel, overhead_cycles, overhead_bits; > > + u32 phy_timing0, phy_timing1, phy_timing2, phy_timing3; > > + u32 ui, cycle_time; > > > > if (++dsi->refcount != 1) > > return 0; > > > > + switch (dsi->format) { > > + case MIPI_DSI_FMT_RGB565: > > + bit_per_pixel = 16; > > + break; > > + case MIPI_DSI_FMT_RGB666_PACKED: > > + bit_per_pixel = 18; > > + break; > > + case MIPI_DSI_FMT_RGB666: > > + case MIPI_DSI_FMT_RGB888: > > + default: > > + bit_per_pixel = 24; > > + break; > > + } > > + /** > > + * data_rate = (pixel_clock) * bit_per_pixel * mipi_ratio / lane_num; > > + * vm.pixelclock is Khz, data_rata unit is Hz, so need to multiply 1000 > > + * mipi_ratio is (htotal * byte_per_pixel / lane_num + Tlpx + Ths_prep > > + * + Thstrail + Ths_exit + Ths_zero) / > > + * (htotal * byte_per_pixel /lane_number) > > + */ > > + bit_clock = dsi->vm.pixelclock * 1000 * bit_per_pixel; > > + htotal = dsi->vm.hactive + dsi->vm.hback_porch + dsi->vm.hfront_porch + > > + dsi->vm.hsync_len; > > + htotal_bits = htotal * bit_per_pixel; > > + > > /** > > - * data_rate = (pixel_clock / 1000) * pixel_dipth * mipi_ratio; > > - * pixel_clock unit is Khz, data_rata unit is MHz, so need divide 1000. > > - * mipi_ratio is mipi clk coefficient for balance the pixel clk in mipi. > > - * we set mipi_ratio is 1.05. > > + * overhead = lpx + hs_prepare + hs_zero + hs_trail + hs_exit > > */ > > - dsi->data_rate = dsi->vm.pixelclock * 3 * 21 / (1 * 1000 * 10); > > + overhead_cycles = LPX + (HS_PRPR >> 8) + (HS_ZERO >> 16) + > > + (HS_TRAIL >> 24) + (DA_HS_EXIT >> 24); > > + overhead_bits = overhead_cycles * dsi->lanes * 8; > > + total_bits = htotal_bits + overhead_bits; > > > > - ret = clk_set_rate(dsi->hs_clk, dsi->data_rate * 1000000); > > + dsi->data_rate = DIV_ROUND_UP_ULL(bit_clock * total_bits, > > + htotal_bits * dsi->lanes); > > + > > + ret = clk_set_rate(dsi->hs_clk, dsi->data_rate); > > if (ret < 0) { > > dev_err(dev, "Failed to set data rate: %d\n", ret); > > goto err_refcount; > > @@ -236,7 +254,20 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) > > > > mtk_dsi_enable(dsi); > > mtk_dsi_reset(dsi); > > - dsi_phy_timconfig(dsi); > > + > > + ui = 1000 / dsi->data_rate + 0x01; > > + cycle_time = 8000 / dsi->data_rate + 0x01; > > + > > + phy_timing0 = LPX | HS_PRPR | HS_ZERO | HS_TRAIL; > > + phy_timing1 = TA_GO | TA_SURE | TA_GET | DA_HS_EXIT; > > + phy_timing2 = ((NS_TO_CYCLE(0x64, cycle_time) + 0xa) << 24) | > > + (NS_TO_CYCLE(0x150, cycle_time) << 16); > > + phy_timing3 = (2 * LPX) << 16 | > > + NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8 | > > + NS_TO_CYCLE(0x40, cycle_time); > > + > > + dsi_phy_timconfig(dsi, phy_timing0, phy_timing1, phy_timing2, > > + phy_timing3); > > > > return 0; > > > >