linux-kernel - Re: [PATCH v3 2/3] spi: spi-cadence: supports transmission with bits_per

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: <0dbf3a5b-6a60-46d8-a358-61b8d527a8da@sirena.org.uk>
Date: Wed, 14 Jan 2026 14:16:39 +0000
From: Mark Brown <broonie@...nel.org>
To: Rodrigo Alencar <455.rodrigo.alencar@...il.com>
Cc: Jun Guo <jun.guo@...tech.com>, peter.chen@...tech.com,
	fugang.duan@...tech.com, robh@...nel.org, krzk+dt@...nel.org,
	conor+dt@...nel.org, linux-spi@...r.kernel.org,
	michal.simek@....com, cix-kernel-upstream@...tech.com,
	linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/3] spi: spi-cadence: supports transmission with
 bits_per_word of 16 and 32

On Wed, Jan 14, 2026 at 02:14:35PM +0000, Rodrigo Alencar wrote:
> On 25/10/31 03:30PM, Jun Guo wrote:

> > +	if (xspi->txbuf) {
> > +		switch (xspi->n_bytes) {
> > +		case CDNS_SPI_N_BYTES_U8:
> > +			txw = *(u8 *)xspi->txbuf;
> > +			break;

> > +		cdns_spi_write(xspi, CDNS_SPI_TXD, txw);
> > +		xspi->txbuf = (u8 *)xspi->txbuf + xspi->n_bytes;
> > +	}

> cdns_spi_write(xspi, CDNS_SPI_TXD, txw) needs to be called regardless of xspi->txbuf.
> Otherwise, there will be no clock for the read operation to work.
> This is a bug I am seeing on a Zedboard running on 6.19

So the device needs to be flagged as SPI_CONTROLLER_MUST_TX?

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)