linux-kernel - Re: [PATCH RESEND 2/3] arm64: dts: qcom: sc8280xp: Add GPI DMA configuration

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <550a7ead-99a8-44ac-af49-c0e9d79c35c9@linaro.org>
Date: Thu, 5 Jun 2025 15:48:04 +0300
From: Eugen Hristev <eugen.hristev@...aro.org>
To: Pengyu Luo <mitltlatltl@...il.com>, Vinod Koul <vkoul@...nel.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Bjorn Andersson <andersson@...nel.org>,
 Konrad Dybcio <konradybcio@...nel.org>,
 Dmitry Baryshkov <dmitry.baryshkov@...ndries.io>
Cc: linux-arm-msm@...r.kernel.org, dmaengine@...r.kernel.org,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH RESEND 2/3] arm64: dts: qcom: sc8280xp: Add GPI DMA
 configuration



On 6/5/25 10:54, Pengyu Luo wrote:
> SPI on SC8280XP requires DMA (GSI) mode to function properly. Without it,
> SPI controllers fall back to FIFO mode, which causes:
> 
> [    0.901296] geni_spi 898000.spi: error -ENODEV: Failed to get tx DMA ch
> [    0.901305] geni_spi 898000.spi: FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode
> ...
> [   45.605974] goodix-spi-hid spi0.0: SPI transfer timed out
> [   45.605988] geni_spi 898000.spi: Can't set CS when prev xfer running
> [   46.621555] spi_master spi0: failed to transfer one message from queue
> [   46.621568] spi_master spi0: noqueue transfer failed
> [   46.621577] goodix-spi-hid spi0.0: spi transfer error: -110
> [   46.621585] goodix-spi-hid spi0.0: probe with driver goodix-spi-hid failed with error -110
> 
> Therefore, add GPI DMA controller nodes for qup{0,1,2}, and add DMA
> channels for SPI and I2C, UART is excluded for now, as it does not
> yet support this mode.
> 
> Note that, since there is no public schematic, this configuration

Device tree should describe the hardware, not hold a configuration. If
you are configuring hardware, DT is not the place for this. Same goes
for the commit short message.

> is derived from Windows drivers. The drivers do not expose any DMA
> channel mask information, so all available channels are enabled.
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@...il.com>