From: Florian Fainelli <f.fainelli@gmail.com>
To: Tobias Schramm <t.schramm@manjaro.org>,
Rob Herring <robh+dt@kernel.org>,
Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: devicetree@vger.kernel.org,
bcm-kernel-feedback-list@broadcom.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] ARM: dts: bcm2711: Enable ddr modes on emmc2 controller
Date: Mon, 31 Aug 2020 15:00:20 -0700 [thread overview]
Message-ID: <7ff055aa-08c3-4b91-f710-a1f7777b1c5f@gmail.com> (raw)
In-Reply-To: <20200829231509.543901-2-t.schramm@manjaro.org>
On 8/29/2020 4:15 PM, Tobias Schramm wrote:
> This patch enables ddr modes for eMMC and SD storage on emmc2,
> doubling transfer speed. Previously only single data rate modes were
> used, wasting half the available throughput.
> The bcm2711 supports both SD and eMMC storage using ddr modes. Testing
> show that pcb layout of the Raspberry Pi 4 can support them, too.
>
> Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
This depends on Stefan's patch here:
https://lore.kernel.org/linux-arm-kernel/1598651234-29826-1-git-send-email-stefan.wahren@i2se.com/
I am fine with us taking the DTS patch, as long as they all land in 5.10
at some point.
> ---
> arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> index 222d7825e1ab..8b61e258e906 100644
> --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> @@ -191,6 +191,8 @@ &emmc2 {
> vqmmc-supply = <&sd_io_1v8_reg>;
> vmmc-supply = <&sd_vcc_reg>;
> broken-cd;
> + mmc-ddr-3_3v;
> + sd-uhs-ddr50;
> status = "okay";
> };
>
>
--
Florian
prev parent reply other threads:[~2020-08-31 22:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-29 23:15 [PATCH 0/1] Enable ddr modes on emmc2 of Raspberry Pi 4 B Tobias Schramm
2020-08-29 23:15 ` [PATCH 1/1] ARM: dts: bcm2711: Enable ddr modes on emmc2 controller Tobias Schramm
2020-08-31 22:00 ` Florian Fainelli [this message]
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