Re: [PATCH] staging: vchiq_arm: Add 36-bit address support

From: Dan Carpenter <dan.carpenter@oracle.com>
To: Mwesigwa Guma <mguma@redhat.com>
Cc: linux-kernel@vger.kernel.org,
	Nicolas Saenz Julienne <nsaenz@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Stefan Wahren <stefan.wahren@i2se.com>,
	Ojaswin Mujoo <ojaswin98@gmail.com>,
	Amarjargal Gundjalam <amarjargal16@gmail.com>,
	Phil Elwell <phil@raspberrypi.com>,
	bcm-kernel-feedback-list@broadcom.com,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-staging@lists.linux.dev, fedora-rpi@googlegroups.com,
	Joel Savitz <jsavitz@redhat.com>,
	Chukpozohn Toe <ctoe@redhat.com>,
	Clark Williams <clark@redhat.com>
Subject: Re: [PATCH] staging: vchiq_arm: Add 36-bit address support
Date: Fri, 15 Oct 2021 10:30:42 +0300	[thread overview]
Message-ID: <20211015073042.GP8429@kadam> (raw)
In-Reply-To: <20211014223230.451659-1-mguma@redhat.com>

On Thu, Oct 14, 2021 at 06:32:30PM -0400, Mwesigwa Guma wrote:
> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Stefan Wahren <stefan.wahren@i2se.com>
> Cc: Ojaswin Mujoo <ojaswin98@gmail.com>
> Cc: Dan Carpenter <dan.carpenter@oracle.com>
> Cc: Amarjargal Gundjalam <amarjargal16@gmail.com>
> Cc: Phil Elwell <phil@raspberrypi.com>
> Cc: bcm-kernel-feedback-list@broadcom.com
> Cc: linux-rpi-kernel@lists.infradead.org 
> Cc: linux-arm-kernel@lists.infradead.org 
> Cc: linux-staging@lists.linux.dev 
> Cc: fedora-rpi@googlegroups.com
> Cc: Joel Savitz <jsavitz@redhat.com>
> Cc: Chukpozohn Toe <ctoe@redhat.com>
> Cc: Clark Williams <clark@redhat.com>
> 

Did you intend to put this CC list here?  It goes at the end next to
the Signed-off-by line if so.  I don't feel like it's required except
maybe Phil to show he was Cc'd.

> This is a forward port of Phil Elwell's commit from the Raspberry Pi
> Linux fork described as follows [1]:

Please use the From: header to give authorship credit.

From: Phil Elwell <phil@raspberrypi.com>

Make that the first line of the email.

> 
>     Conditional on a new compatible string, change the pagelist encoding
>     such that the top 24 bits are the pfn, leaving 8 bits for run length
>     (-1), giving a 36-bit address range.
>     
>     Manage the split between addresses for the VPU and addresses for the
>     40-bit DMA controller with a dedicated DMA device pointer that on non-
>     BCM2711 platforms is the same as the main VCHIQ device. This allows
>     the VCHIQ node to stay in the usual place in the DT.
> 
> This commit enables VCHIQ device access on a Raspberry Pi 4B running the 
> mainline Linux kernel.
> 
> Tested on Fedora Linux running on a Raspberry Pi 4B.
> 
> [1]: https://github.com/raspberrypi/linux/commit/97268fd23eb8d08dc74eac5e3fd697303de26610
> 
> Signed-off-by: Mwesigwa Guma <mguma@redhat.com>

regards,
dan carpenter