From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 387743DF010 for ; Wed, 22 Apr 2026 12:38:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776861525; cv=none; b=Eipvohx1vaKoD7Wtw1HLN8mVgFV66C1c2hdyG0Qr+YWhntxBdP7YI8w+e4P906MnNCmILGDs6OEcy0uQOPMFNngYXmQCiS78DTD5mZetsUsSiyZ0wJ8NZ/JP5bmfXL0FUSutruTA/DmaYqyc9F16wzlshc8d/cjy7OGHNGdfTN8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776861525; c=relaxed/simple; bh=xH0Kba6RWmQUQR7OixHbv50JcWu3NtwEQ2BrXjkN5oQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P1nfrgty7/392epv7AVVJfltlRMsu+Ow3GOjBeO0Hf5sBdAfrCH/MenK8auQH+nAuDJSqueoOfSEIa6SwyLUWbMt+l+cuwJdjX88V4+vAen5hB+AZL6SeFPMBgCGVK5qqRQ7bYd0WKez2Ig727KMFX4iGurAYp3QmI16gDufVfQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Ew4SGDvd; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Ew4SGDvd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776861522; x=1808397522; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=xH0Kba6RWmQUQR7OixHbv50JcWu3NtwEQ2BrXjkN5oQ=; b=Ew4SGDvdghrPTYKrwa6i1s6y57O1t7CXOsg6KEjGuN1EsuX6DQFzUfBu 7ga4XLoP/7goXWKKk+c3P/uaiKWwSwl2qzXefRmJqCE5511bfiIaPW4A8 sLPpNckZe44JnSRwB6JUMdYZczNY9uTSWYnIbwNxkRakls9bzuo19l/Vw bgl6Qk4kwHnTrrP8Yd05o1zA8T+rHpP7qmQYBU0e42AGIkLGmfVYb1MLu jlWGpYXF0C6tV+JFNv9S3zuIuf3iHjvlfE8NEC2ZZX6I54AzHSzSoUxpV BqyK89YmPB/zYLv6pADS6iOH0TKRvCRp7UnQMxwsphRDOjGUYmusljnqd A==; X-CSE-ConnectionGUID: Aw+6F4fpRn692lpxf+HdIw== X-CSE-MsgGUID: Fk6md5GcRimVq7MmgcLb0A== X-IronPort-AV: E=McAfee;i="6800,10657,11764"; a="65347346" X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="65347346" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2026 05:38:41 -0700 X-CSE-ConnectionGUID: OwpGkRE8RMCPSNu5QwZu+Q== X-CSE-MsgGUID: 8DruK/aXT3ONHvVy/Iyrvg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="236714989" Received: from dhhellew-desk2.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.245.245.208]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2026 05:38:39 -0700 Received: from kekkonen.localdomain (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with SMTP id DFDC7120D05; Wed, 22 Apr 2026 15:38:36 +0300 (EEST) Date: Wed, 22 Apr 2026 15:38:36 +0300 Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo From: Sakari Ailus To: Debjeet Banerjee Cc: andy.shevchenko@gmail.com, andy@kernel.org, gregkh@linuxfoundation.org, hansg@kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-staging@lists.linux.dev, mchehab@kernel.org Subject: Re: [PATCH v4 1/2] media: atomisp: csi2: Remove unimplemented DPCM decompression Message-ID: References: <20260422122006.29390-1-debjeetbanerjee48@gmail.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260422122006.29390-1-debjeetbanerjee48@gmail.com> Hi Debjeet, On Wed, Apr 22, 2026 at 05:50:05PM +0530, Debjeet Banerjee wrote: > The source pad format handling attempted to map DPCM-compressed mbus > codes to their uncompressed equivalents. However, the rest of the > driver does not support DPCM decompression, making this dead code. > > Remove the DPCM unmapping logic and simplify to directly copy the sink > pad format to the source pad. Add an explicit comment stating that > DPCM is not supported. > > Signed-off-by: Debjeet Banerjee > --- > v4: > - Complete removal of DPCM decompression attempt (per Sakari Ailus feedback) > - Keep source pad simply copying sink pad format without unmapping > - Replace detailed comment with explicit "DPCM is not supported" statement > > v3: > - Drop "staging:" prefix in subject (per Andy Shevchenko) > > v2: > - Rebased onto latest media tree (fix CI apply failure) > - Fix missing linux-staging recipient (typo in v1) > - Fix indentation > --- > drivers/staging/media/atomisp/pci/atomisp_csi2.c | 15 ++++----------- > 1 file changed, 4 insertions(+), 11 deletions(-) > > diff --git a/drivers/staging/media/atomisp/pci/atomisp_csi2.c b/drivers/staging/media/atomisp/pci/atomisp_csi2.c > index e723304bec80..64419c1a805e 100644 > --- a/drivers/staging/media/atomisp/pci/atomisp_csi2.c > +++ b/drivers/staging/media/atomisp/pci/atomisp_csi2.c > @@ -107,17 +107,10 @@ int atomisp_csi2_set_ffmt(struct v4l2_subdev *sd, > &tmp_ffmt); > } > > - /* > - * The source pad must expose the uncompressed format even when the sink > - * pad receives DPCM-compressed data. The hardware decompresses DPCM > - * (e.g. SGRBG10_DPCM8_1X8 -> SGRBG10_1X10) between sink and source, > - * so propagate the sink format but map the mbus code to its uncompressed > - * equivalent. atomisp_subdev_uncompressed_code() returns the code > - * unchanged for formats that are not DPCM-compressed. > - */ > - *actual_ffmt = *__csi2_get_format(csi2, sd_state, which, CSI2_PAD_SINK); > - actual_ffmt->code = atomisp_subdev_uncompressed_code(actual_ffmt->code); > - *ffmt = *actual_ffmt; This won't apply to my atomisp branch. > + /* Source pad format is copied from sink pad. DPCM is not supported. */ > + *actual_ffmt = *ffmt = *__csi2_get_format(csi2, sd_state, which, > + CSI2_PAD_SINK); > + > return 0; > } > -- Regards, Sakari Ailus