From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1383F231A49; Wed, 15 Jan 2025 10:26:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736936767; cv=none; b=qjgmn5ra79TwGHpwMPAYbEYyDdQLMa5hHHERiBfRdi8arP8Re+5ZIrHSVYjdK2fkq8TT4lgR9VXJoXNwPtxidcOiQBFMEztrnes4KuH1eSl4dU/lVT4sDHvCYknDArhOefmr+lkFRDE2ZuwF+QvDrjFBYLYaefK9xbXr1uW33xU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736936767; c=relaxed/simple; bh=DlgzPybJLohqJTRasUTNfTcIW6PVnJn4Ey+QYJaNbJ8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ObGObsEUO30EaZ9PNU4P4G4ucPlO+YwydwRfoTxnUEqh3tiXBLMghvLd6qeBqbQtybkPB45Qpvwk7FBoxeKrqQpeMogDLxbOiV3BLrm1/ydeapu3v1yNS2cPmGkdNXKP+1rQMfvKTleLwta1P6jQzjKbXVzJX9XpEylk4ToPl9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Mljgl0Dv; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=qI2Y6oN0; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Mljgl0Dv; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=qI2Y6oN0; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Mljgl0Dv"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="qI2Y6oN0"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Mljgl0Dv"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="qI2Y6oN0" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 3A60921285; Wed, 15 Jan 2025 10:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1736936763; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=o5OaTSBvndaqL7pmKVkJ0tKcrkXR4wXg7zZA1xwdifc=; b=Mljgl0DvQXsyKMdMzmz5ZwZ3V789zCdVdhgaCjuMtwHrT61J2CLPcsqyigpgNfMgt5s9ED NQBLa2bFnxQBC6Lh8kmGl4ElL6IbxkHaMKnpSDKgAWvZ5RgKmpAEVOTkk2jS/7Dqz07SiL vCLaFHZP1mmjRXmvQ/ScFe4UhJimBB4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1736936763; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=o5OaTSBvndaqL7pmKVkJ0tKcrkXR4wXg7zZA1xwdifc=; b=qI2Y6oN0l9JxGfh+RN+mqlivvJYcBaYsV/e1PTdXmK0ZMZeCqm75AAiZVcbCx5W/dssHYm 9npljUHucuH2iADw== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1736936763; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=o5OaTSBvndaqL7pmKVkJ0tKcrkXR4wXg7zZA1xwdifc=; b=Mljgl0DvQXsyKMdMzmz5ZwZ3V789zCdVdhgaCjuMtwHrT61J2CLPcsqyigpgNfMgt5s9ED NQBLa2bFnxQBC6Lh8kmGl4ElL6IbxkHaMKnpSDKgAWvZ5RgKmpAEVOTkk2jS/7Dqz07SiL vCLaFHZP1mmjRXmvQ/ScFe4UhJimBB4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1736936763; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=o5OaTSBvndaqL7pmKVkJ0tKcrkXR4wXg7zZA1xwdifc=; b=qI2Y6oN0l9JxGfh+RN+mqlivvJYcBaYsV/e1PTdXmK0ZMZeCqm75AAiZVcbCx5W/dssHYm 9npljUHucuH2iADw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id B2519139CB; Wed, 15 Jan 2025 10:26:02 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id yds5KjqNh2dqKAAAD6G6ig (envelope-from ); Wed, 15 Jan 2025 10:26:02 +0000 Message-ID: Date: Wed, 15 Jan 2025 11:26:02 +0100 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 25/25] drm/xlnx: Compute dumb-buffer sizes with drm_mode_size_dumb() To: Tomi Valkeinen , maarten.lankhorst@linux.intel.com, mripard@kernel.org, airlied@gmail.com, simona@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, imx@lists.linux.dev, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-tegra@vger.kernel.org, intel-xe@lists.freedesktop.org, xen-devel@lists.xenproject.org, Laurent Pinchart References: <20250109150310.219442-1-tzimmermann@suse.de> <20250109150310.219442-26-tzimmermann@suse.de> Content-Language: en-US From: Thomas Zimmermann Autocrypt: addr=tzimmermann@suse.de; keydata= xsBNBFs50uABCADEHPidWt974CaxBVbrIBwqcq/WURinJ3+2WlIrKWspiP83vfZKaXhFYsdg XH47fDVbPPj+d6tQrw5lPQCyqjwrCPYnq3WlIBnGPJ4/jreTL6V+qfKRDlGLWFjZcsrPJGE0 BeB5BbqP5erN1qylK9i3gPoQjXGhpBpQYwRrEyQyjuvk+Ev0K1Jc5tVDeJAuau3TGNgah4Yc hdHm3bkPjz9EErV85RwvImQ1dptvx6s7xzwXTgGAsaYZsL8WCwDaTuqFa1d1jjlaxg6+tZsB 9GluwvIhSezPgnEmimZDkGnZRRSFiGP8yjqTjjWuf0bSj5rUnTGiyLyRZRNGcXmu6hjlABEB AAHNJ1Rob21hcyBaaW1tZXJtYW5uIDx0emltbWVybWFubkBzdXNlLmRlPsLAjgQTAQgAOAIb AwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftODH AAoJEGgNwR1TC3ojx1wH/0hKGWugiqDgLNXLRD/4TfHBEKmxIrmfu9Z5t7vwUKfwhFL6hqvo lXPJJKQpQ2z8+X2vZm/slsLn7J1yjrOsoJhKABDi+3QWWSGkaGwRJAdPVVyJMfJRNNNIKwVb U6B1BkX2XDKDGffF4TxlOpSQzdtNI/9gleOoUA8+jy8knnDYzjBNOZqLG2FuTdicBXblz0Mf vg41gd9kCwYXDnD91rJU8tzylXv03E75NCaTxTM+FBXPmsAVYQ4GYhhgFt8S2UWMoaaABLDe 7l5FdnLdDEcbmd8uLU2CaG4W2cLrUaI4jz2XbkcPQkqTQ3EB67hYkjiEE6Zy3ggOitiQGcqp j//OwE0EWznS4AEIAMYmP4M/V+T5RY5at/g7rUdNsLhWv1APYrh9RQefODYHrNRHUE9eosYb T6XMryR9hT8XlGOYRwKWwiQBoWSDiTMo/Xi29jUnn4BXfI2px2DTXwc22LKtLAgTRjP+qbU6 3Y0xnQN29UGDbYgyyK51DW3H0If2a3JNsheAAK+Xc9baj0LGIc8T9uiEWHBnCH+RdhgATnWW GKdDegUR5BkDfDg5O/FISymJBHx2Dyoklv5g4BzkgqTqwmaYzsl8UxZKvbaxq0zbehDda8lv hFXodNFMAgTLJlLuDYOGLK2AwbrS3Sp0AEbkpdJBb44qVlGm5bApZouHeJ/+n+7r12+lqdsA EQEAAcLAdgQYAQgAIAIbDBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftOH6AAoJEGgNwR1T C3ojVSkIALpAPkIJPQoURPb1VWjh34l0HlglmYHvZszJWTXYwavHR8+k6Baa6H7ufXNQtThR yIxJrQLW6rV5lm7TjhffEhxVCn37+cg0zZ3j7zIsSS0rx/aMwi6VhFJA5hfn3T0TtrijKP4A SAQO9xD1Zk9/61JWk8OysuIh7MXkl0fxbRKWE93XeQBhIJHQfnc+YBLprdnxR446Sh8Wn/2D Ya8cavuWf2zrB6cZurs048xe0UbSW5AOSo4V9M0jzYI4nZqTmPxYyXbm30Kvmz0rYVRaitYJ 4kyYYMhuULvrJDMjZRvaNe52tkKAvMevcGdt38H4KSVXAylqyQOW5zvPc4/sq9c= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Level: X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; FREEMAIL_TO(0.00)[ideasonboard.com,linux.intel.com,kernel.org,gmail.com,ffwll.ch]; RCPT_COUNT_TWELVE(0.00)[20]; MIME_TRACE(0.00)[0:+]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:mid] X-Spam-Score: -2.80 X-Spam-Flag: NO Hi Am 15.01.25 um 11:13 schrieb Tomi Valkeinen: > Hi! > > On 09/01/2025 16:57, Thomas Zimmermann wrote: >> Call drm_mode_size_dumb() to compute dumb-buffer scanline pitch and >> buffer size. Align the pitch according to hardware requirements. >> >> Signed-off-by: Thomas Zimmermann >> Cc: Laurent Pinchart >> Cc: Tomi Valkeinen >> --- >>   drivers/gpu/drm/xlnx/zynqmp_kms.c | 7 +++++-- >>   1 file changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c >> b/drivers/gpu/drm/xlnx/zynqmp_kms.c >> index b47463473472..7ea0cd4f71d3 100644 >> --- a/drivers/gpu/drm/xlnx/zynqmp_kms.c >> +++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c >> @@ -19,6 +19,7 @@ >>   #include >>   #include >>   #include >> +#include >>   #include >>   #include >>   #include >> @@ -363,10 +364,12 @@ static int zynqmp_dpsub_dumb_create(struct >> drm_file *file_priv, >>                       struct drm_mode_create_dumb *args) >>   { >>       struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(drm); >> -    unsigned int pitch = DIV_ROUND_UP(args->width * args->bpp, 8); >> +    int ret; >>         /* Enforce the alignment constraints of the DMA engine. */ >> -    args->pitch = ALIGN(pitch, dpsub->dma_align); >> +    ret = drm_mode_size_dumb(drm, args, dpsub->dma_align, 0); >> +    if (ret) >> +        return ret; >>         return drm_gem_dma_dumb_create_internal(file_priv, drm, args); >>   } > > I have some trouble with this one. > > I have sent a series to add some pixel formats: > > https://lore.kernel.org/all/20250115-xilinx-formats-v2-0-160327ca652a@ideasonboard.com/ > > > Let's look at XV15. It's similar to NV12, but 10 bits per component, > and some packing and padding. > > First plane: 3 pixels in a 32 bit group > Second plane: 3 pixels in a 64 bit group, 2x2 subsampled > > So, on average, a pixel on the first plane takes 32 / 3 = 10.666... > bits on a line. That's not a usable number for the > DRM_IOCTL_MODE_CREATE_DUMB ioctl. > > What I did was to use the pixel group size as "bpp" for > DRM_IOCTL_MODE_CREATE_DUMB. So, e.g., for 720 x 576: > > Stride for first plane: 720 * (32 / 3) / 8 = 960 bytes > Stride for second plane: 720 / 2 * (64 / 3) / 8 = 960 bytes > > First plane: 720 / 3 = 240 pixel groups > Second plane: 720 / 2 / 3 = 120 pixel groups > > So I allocated the two planes with: > 240 x 576 with 32 bitspp > 120 x 288 with 64 bitspp > > This worked, and if I look at the DRM_IOCTL_MODE_CREATE_DUMB in the > docs, I can't right away see anything there that says my tactic was > not allowed. > > The above doesn't work anymore with this patch, as the code calls > drm_driver_color_mode_format(), which fails for 64 bitspp. It feels a > bit odd that DRM_IOCTL_MODE_CREATE_DUMB will try to guess the RGB > fourcc for a dumb buffer allocation. > > So, what to do here? Am I doing something silly? What's the correct > way to allocate the buffers for XV15? Should I just use 32 bitspp for > the plane 2 too, and double the width (this works)? > > Is DRM_IOCTL_MODE_CREATE_DUMB only meant for simple RGB formats? The > xilinx driver can, of course, just not use drm_mode_size_dumb(). But > if so, I guess the limitations of drm_mode_size_dumb() should be > documented. > > Do we need a new dumb-alloc ioctl that takes the format and plane > number as parameters? Or alternatively a simpler dumb-alloc that > doesn't have width and bpp, but instead takes a stride and height as > parameters? I think those would be easier for the userspace to use, > instead of trying to adjust the parameters to be suitable for the kernel. These are all good points. Did you read my discussion with Andy on patch 2? I think it resolves all the points you have. The current CREATE_DUMB ioctl is unsuited for anything but the simple RGB formats. The bpp parameter is not very precise. The solution would be a new ioctl call that receives the DRM format and returns a buffer for each individual plane. I provided a workaround patch that uses the bpp value directly if drm_driver_color_mode_format() does not support the bpp value. User-space code has to allocate a large enough buffer via the current CREATE_DUMB and compute the individual planes itself. See [1] for an example. [1] https://gitlab.freedesktop.org/mesa/drm/-/blob/main/tests/modetest/buffers.c?ref_type=heads#L302 Does this work for you? Otherwise, I guess we should be talking about a possible CREATE_DUMB2 that fixes these shortcomings. Best regards Thomas > >  Tomi > -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)