From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ea0-f178.google.com ([209.85.215.178]:45209 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753624Ab3CXMzX (ORCPT ); Sun, 24 Mar 2013 08:55:23 -0400 Received: by mail-ea0-f178.google.com with SMTP id g14so2012276eak.23 for ; Sun, 24 Mar 2013 05:55:22 -0700 (PDT) Message-ID: <514EF7F2.9000405@googlemail.com> Date: Sun, 24 Mar 2013 13:56:18 +0100 From: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Linux Media Mailing List Subject: Re: [PATCH v2 5/5] em28xx: write output frame resolution to regs 0x34+0x35 for em25xx family bridges References: <1364059632-29070-1-git-send-email-fschaefer.oss@googlemail.com> <1364059632-29070-6-git-send-email-fschaefer.oss@googlemail.com> <20130324084436.76968b9e@redhat.com> In-Reply-To: <20130324084436.76968b9e@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Am 24.03.2013 12:44, schrieb Mauro Carvalho Chehab: > Em Sat, 23 Mar 2013 18:27:12 +0100 > Frank Schäfer escreveu: > >> The Windows driver writes the output resolution to registers 0x34 (width / 16) >> and 0x35 (height / 16) always. >> We don't know yet what these registers are used for. >> >> Signed-off-by: Frank Schäfer >> --- >> drivers/media/usb/em28xx/em28xx-core.c | 7 +++++++ >> drivers/media/usb/em28xx/em28xx-reg.h | 6 ++++++ >> 2 Dateien geändert, 13 Zeilen hinzugefügt(+) >> >> diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c >> index 7b9f76b..0ce6b0f 100644 >> --- a/drivers/media/usb/em28xx/em28xx-core.c >> +++ b/drivers/media/usb/em28xx/em28xx-core.c >> @@ -766,6 +766,13 @@ static void em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart, >> em28xx_write_regs(dev, EM28XX_R1E_CWIDTH, &cwidth, 1); >> em28xx_write_regs(dev, EM28XX_R1F_CHEIGHT, &cheight, 1); >> em28xx_write_regs(dev, EM28XX_R1B_OFLOW, &overflow, 1); >> + >> + if (dev->is_em25xx) { >> + em28xx_write_reg(dev, 0x34, width >> 4); >> + em28xx_write_reg(dev, 0x35, height >> 4); >> + } >> + /* FIXME: function/meaning of these registers ? */ >> + /* FIXME: align width+height to multiples of 4 ?! */ > Please move those comments to be _before_ the code you're commenting. > > E. g. something like: > > if (dev->is_em25xx) { > /* > * FIXME: > * - function/meaning of these registers are unknown; > * - align width+height to multiples of 4 ?! > */ > em28xx_write_reg(dev, 0x34, width >> 4); > em28xx_write_reg(dev, 0x35, height >> 4); > } Ok, no problem. Frank > >> } >> >> static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v) >> diff --git a/drivers/media/usb/em28xx/em28xx-reg.h b/drivers/media/usb/em28xx/em28xx-reg.h >> index 1b0ecd6..e08982a 100644 >> --- a/drivers/media/usb/em28xx/em28xx-reg.h >> +++ b/drivers/media/usb/em28xx/em28xx-reg.h >> @@ -167,6 +167,12 @@ >> >> #define EM28XX_R34_VBI_START_H 0x34 >> #define EM28XX_R35_VBI_START_V 0x35 >> +/* NOTE: the EM276x (and EM25xx, EM277x/8x ?) (camera bridges) use these >> + * registers for a different unknown purpose. >> + * => register 0x34 is set to capture width / 16 >> + * => register 0x35 is set to capture height / 16 >> + */ >> + >> #define EM28XX_R36_VBI_WIDTH 0x36 >> #define EM28XX_R37_VBI_HEIGHT 0x37 >> >