Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751289AbdIKG40 (ORCPT ); Mon, 11 Sep 2017 02:56:26 -0400 Received: from mail-wm0-f45.google.com ([74.125.82.45]:45832 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202AbdIKG4X (ORCPT ); Mon, 11 Sep 2017 02:56:23 -0400 X-Google-Smtp-Source: AOwi7QDC+qrzajwyJ85Z5e4miFlu2mYVLbpjYNT469FtX8P2JVe2DzXOdLLXWMOgkk9TdbyFVVQb2g== Subject: Re: [PATCH v4 12/21] camss: vfe: Format conversion support using PIX interface To: Geert Uytterhoeven Cc: Mauro Carvalho Chehab , Hans Verkuil , Sylwester Nawrocki , Sakari Ailus , Linux Media Mailing List , "linux-kernel@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , Arnd Bergmann References: <1502199018-28250-1-git-send-email-todor.tomov@linaro.org> <1502199018-28250-13-git-send-email-todor.tomov@linaro.org> From: Todor Tomov Message-ID: <5fdb0554-51b7-29e3-34ee-d79c46194253@linaro.org> Date: Mon, 11 Sep 2017 09:56:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4214 Lines: 121 Hi Geert, On 10.09.2017 12:58, Geert Uytterhoeven wrote: > Hi Todor, > > On Tue, Aug 8, 2017 at 3:30 PM, Todor Tomov wrote: >> Use VFE PIX input interface and do format conversion in VFE. >> >> Supported input format is UYVY (single plane YUV 4:2:2) and >> its different sample order variations. >> >> Supported output formats are: >> - NV12/NV21 (two plane YUV 4:2:0) >> - NV16/NV61 (two plane YUV 4:2:2) >> >> Signed-off-by: Todor Tomov > > This is now commit 9b5833f7b82f1431 upstream. > >> @@ -355,6 +471,38 @@ static void vfe_bus_disconnect_wm_from_rdi(struct vfe_device *vfe, u8 wm, >> vfe_reg_clr(vfe, VFE_0_BUS_XBAR_CFG_x(wm), reg); >> } >> >> +static void vfe_set_xbar_cfg(struct vfe_device *vfe, struct vfe_output *output, >> + u8 enable) >> +{ >> + struct vfe_line *line = container_of(output, struct vfe_line, output); >> + u32 p = line->video_out.active_fmt.fmt.pix_mp.pixelformat; >> + u32 reg; > > With gcc 4.1.2: > > drivers/media/platform/qcom/camss-8x16/camss-vfe.c: In function > ‘vfe_set_xbar_cfg’: > drivers/media/platform/qcom/camss-8x16/camss-vfe.c:614: warning: > ‘reg’ may be used uninitialized in this function > > This is a false positive, as output->wm_num is always either 1 or 2, hence the > index i can never have a value different from 0 or 1, and reg is thus always > initialized. > >> + unsigned int i; >> + >> + for (i = 0; i < output->wm_num; i++) { >> + if (i == 0) { >> + reg = VFE_0_BUS_XBAR_CFG_x_M_SINGLE_STREAM_SEL_LUMA << >> + VFE_0_BUS_XBAR_CFG_x_M_SINGLE_STREAM_SEL_SHIFT; >> + } else if (i == 1) { >> + reg = VFE_0_BUS_XBAR_CFG_x_M_PAIR_STREAM_EN; >> + if (p == V4L2_PIX_FMT_NV12 || p == V4L2_PIX_FMT_NV16) >> + reg |= VFE_0_BUS_XBAR_CFG_x_M_PAIR_STREAM_SWAP_INTER_INTRA; >> + } > >> @@ -458,6 +728,10 @@ static void vfe_init_outputs(struct vfe_device *vfe) >> output->buf[0] = NULL; >> output->buf[1] = NULL; >> INIT_LIST_HEAD(&output->pending_bufs); >> + >> + output->wm_num = 1; >> + if (vfe->line[i].id == VFE_LINE_PIX) >> + output->wm_num = 2; >> } >> } >> > >> --- a/drivers/media/platform/qcom/camss-8x16/camss-vfe.h >> +++ b/drivers/media/platform/qcom/camss-8x16/camss-vfe.h >> @@ -30,8 +30,9 @@ >> #define MSM_VFE_PAD_SRC 1 >> #define MSM_VFE_PADS_NUM 2 >> >> -#define MSM_VFE_LINE_NUM 3 >> +#define MSM_VFE_LINE_NUM 4 >> #define MSM_VFE_IMAGE_MASTERS_NUM 7 >> +#define MSM_VFE_COMPOSITE_IRQ_NUM 4 >> >> #define MSM_VFE_VFE0_UB_SIZE 1023 >> #define MSM_VFE_VFE0_UB_SIZE_RDI (MSM_VFE_VFE0_UB_SIZE / 3) >> @@ -51,11 +52,13 @@ enum vfe_line_id { >> VFE_LINE_NONE = -1, >> VFE_LINE_RDI0 = 0, >> VFE_LINE_RDI1 = 1, >> - VFE_LINE_RDI2 = 2 >> + VFE_LINE_RDI2 = 2, >> + VFE_LINE_PIX = 3 >> }; >> >> struct vfe_output { >> - u8 wm_idx; >> + u8 wm_num; >> + u8 wm_idx[3]; > > However, wm_idx[] reserves space for 3 entries, while currently only 2 are > needed. Why? > > If this is meant to accommodate for a future extension, the false positive > will become a real issue. The third entry will be needed if we add any three planar pixel format support to the driver. If this happens this will involve also changes in vfe_set_xbar_cfg() to support it. It is fine to change wm_idx[3] to wm_idx[2] until then. However this will not remove the false positive warning. I suppose it is best to also change vfe_set_xbar_cfg() now so that there is no warning - init reg to 0 in all cases? > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds > -- Best regards, Todor Tomov