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  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]
Date:   Tue, 12 Jan 2021 09:49:44 +0530
From:   Vinod Koul <>
To:     Konrad Dybcio <>
Cc:     Bjorn Andersson <>,
        Mark Brown <>, Wolfram Sang <>,, Andy Gross <>,
        Matthias Kaehlcke <>,
        Douglas Anderson <>,
        Sumit Semwal <>,
        Amit Pundir <>,,,
Subject: Re: [PATCH 7/7] arm64: dts: qcom: sdm845: enable dma for spi

On 11-01-21, 21:45, Konrad Dybcio wrote:
> > If it is working without GPI enabled, it would work.. GPI for QUP is
> > something that requires firmware and would have to be enabled by
> > firmware
> I think with the new code of yours:
> mas->tx = dma_request_slave_channel(mas->dev, "tx");
> + if (IS_ERR_OR_NULL(mas->tx)) {
> + dev_err(mas->dev, "Failed to get tx DMA ch %ld", PTR_ERR(mas->tx)); ret = PTR_ERR(mas->tx); + goto out_pm;

This code would be exercised *only* when DMA mode is enabled in
firmware.. Both SPI and I2C driver would probe the mode supported
(reason for exposing stuff in first two patches of this series)..

Only if the device reports we should enable it.. Also if the device is
working with FIFO mode then DMA mode wont work..

> it *may* fail to probe with the channels assigned in the "dmas="
> property but with the engine having "status=disabled", but as I don't
> have any hardware to test that driver on, please confirm whether my
> concerns are right..
> > Since DMA support may not be available on certain targets (firmware
> > support), so enabling per board would make sense
> Oh really, are there SDM845 boards shipping with GPI DMA *disabled to
> all peripherals*?

Is the peripheral working with FIFO mode, then answer is yes :)


Powered by blists - more mailing lists