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Tue, 11 Jun 2024 15:09:20 +0200 Message-ID: <66aafbbd-b90c-4ca6-80a7-233ec0f6dce6@gmx.net> Date: Tue, 11 Jun 2024 15:09:19 +0200 Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: WARNING: drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:364 vchiq_prepare_bulk_data To: Arnd Bergmann , Robin Murphy , Phil Elwell Cc: "laurent.pinchart" , Catalin Marinas , Will Deacon , Christoph Hellwig , Florian Fainelli , Greg Kroah-Hartman , Linux ARM , linux-staging@lists.linux.dev References: <9d603d43-0f8a-4f9b-b11b-9e7543f421b9@app.fastmail.com> <72a414e4-4cd0-4b12-a662-cb73d1e3515e@app.fastmail.com> <20240610091534.GO18479@pendragon.ideasonboard.com> <28495bd5-41af-41b8-b427-6b6fd36a2740@app.fastmail.com> <04b1276d-4db3-41a5-9960-15e96b779b13@arm.com> <9c2917fa-d2ee-4d0b-b42a-a27191e93088@app.fastmail.com> <5113a1df-858b-4ba1-bd8b-c53c0313c7ce@gmx.net> <87699d92-64f4-4b28-840e-8b320502acb2@app.fastmail.com> Content-Language: en-US From: Stefan Wahren In-Reply-To: <87699d92-64f4-4b28-840e-8b320502acb2@app.fastmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:jHWAQYtLCQLOVZdlsRy0uhZJvvWE/49++jAL7WvO8MSeDxsURHB AfyCpn3rAQNmNv8lhBt47ha7zE6MEWM7mmXjs2BqjK6ZJBJ4Ch2C+JnJzKe8voqV1GpYQJn b1KBf+xdWDeaj/pQUrV1i6/doW7/zpTOg6I6zyclP1+b0fr6XKEed4zSDVqeXJVhsQed673 JIo/3SvVso5JUzMI9mk/g== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:mf+h5EmeDQI=;Az2bjoFsAI5BsknuChA7ZRB5/ad jW58YdFAUxKI8vF581s3yPrRKvln42ybCE6gUGtUh6NeOjkPFEKaQ/FTTAoS4l4rf1PCpXJfi qDgrZtih9oIQbEYboXTxfRxn9UD4pYfpupLXNO7PgjIPyAIu0PuhomWMr4z+5lmOi46kZPPmy zzDu7EfqhQXRqaSXp/F+PCdUmD6zB61OFm7QTPf+cZGGo18Cb7khQBD1Uu2gMtWDGIWHQqNFs 96I5ooA/7FwcZjT8eeEvVXP9pkROKAQn61DVSeWXhtwUh8G0oR/LUfPreERtfnM7ve0H3mmq3 Y3z8t29nbmVKD5mlZqVZkAQKWoZAjDH86VdNFex/z3Yktp5S9mlST4eujUjX+RwEeD4wJ3AoU T/tj1rk0TwWy88RpPKzf+SvMn7YCOUE0voYKwXB/sdTDH9wWkH1LfHXkrqKCHRddQvs8gsgvv x9IW5P5n+1Tpu28NvrOSHzKGzXul1a2BLZ2vOWGRN+3NfD9leaG5Ff9hzk0+0Ynx2Pb5AsgVN +1tNnJsrJtwx43BRzuBGyGUnVtPh2RRJH/VeJT4iVZx+9JE/1r26toH9Zx0te94lR0VXkSh3A dYw2fw2U0/5jwAkbuwK5kupAh67vNSNE4JDCRBucDzTDG1aXt/9P2tyjbNchiBrgL8R2LTko8 wZIh3LN4ROO1TO1WfCSi8urdOFqQ4xbr/IF+z+q+sOzoXude44F4yJLGA28RqTwzNyQfdLNJz FK/R1OOlJTaLSza4nBP3wBZhMD3BDF7DEipoz3oQZPasrDDm5fDItt0MvyER8BUQG0Rx3zUA/ TKLoRW2e55d1yd4/uCNtomHgLUO+bJU3mLCkHqXcefHSc= Hi Arnd, Am 11.06.24 um 14:14 schrieb Arnd Bergmann: > On Tue, Jun 11, 2024, at 13:37, Stefan Wahren wrote: >> Am 11.06.24 um 13:08 schrieb Arnd Bergmann: >>> On Tue, Jun 11, 2024, at 12:47, Stefan Wahren wrote: >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 if (len =3D=3D 0) >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 pr_warn_once= ("%s: sg_dma_len() =3D=3D 0\n", __func__); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 else if (i && (i !=3D (dma_buff= ers - 1)) && (len & ~PAGE_MASK)) >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 pr_warn_once= ("%s: following block not page aligned\n", >> __func__); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 else if (i && (addr & ~PAGE_MAS= K)) { >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 pr_warn_once= ("%s: block %u, DMA address %pad doesn't align >> with PAGE_MASK 0x%lx\n", __func__, i, &addr, PAGE_MASK); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 pr_warn_once= ("sg_dma_is_swiotlb: %d, dma_flags: %x\n", >> sg_dma_is_swiotlb(sg), sg->dma_flags); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 pr_warn_once= ("type =3D %s\n", (type =3D=3D PAGELIST_WRITE) ? >> "PAGELIST_WRITE" : "PAGELIST_READ"); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (buf) >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0= =C2=A0 pr_warn_once("buf =3D %p, count =3D %zu\n", buf, count); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 else >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0= =C2=A0 pr_warn_once("ubuf =3D %p, count =3D %zu\n", ubuf, count); >> =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 } >> >> Output: >> >> [=C2=A0=C2=A0 66.184030] create_pagelist: block 1, DMA address 0x000000= 00f5fc7800 >> doesn't align with PAGE_MASK 0xfffffffffffff000 >> [=C2=A0=C2=A0 66.184056] sg_dma_is_swiotlb: 0, dma_flags: 0 >> [=C2=A0=C2=A0 66.184063] type =3D PAGELIST_READ >> [=C2=A0=C2=A0 66.184066] ubuf =3D 00000000266a70a7, count =3D 0 sorry my debug attempt for count was pointless. The value is always decremented to zero at this point. So your suggested change won't have any effect. > From my reading of the code, it's not really meant to handle > count=3D0, so maybe the answer for that is to just return an > error (or possibly success) when there is data attached to > the request from user space, something like > > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c > @@ -328,6 +328,11 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_= instance *instance, > userdata =3D args->userdata; > } > > + if (!args->size) { > + ret =3D 0; > + goto out; > + } > + > status =3D vchiq_bulk_transfer(instance, args->handle, NULL, ar= gs->data, args->size, > userdata, args->mode, dir); > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel