Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 13 Apr 2022 23:41:34 +0530
From:   Pratyush Yadav <p.yadav@ti.com>
To:     Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
CC:     Mark Brown <broonie@kernel.org>,
        Tudor Ambarus <tudor.ambarus@microchip.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Ramuthevar Vadivel Murugan 
        <vadivel.muruganx.ramuthevar@linux.intel.com>,
        <linux-spi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] spi: cadence-quadspi: fix incorrect supports_op()
 return value
Message-ID: <20220413181134.izsam4fuogl6inbj@ti.com>
References: <20220406132832.199777-1-matthias.schiffer@ew.tq-group.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20220406132832.199777-1-matthias.schiffer@ew.tq-group.com>
Precedence: bulk

On 06/04/22 03:28PM, Matthias Schiffer wrote:
> Since the conversion to spi-mem, the driver advertised support for
> various operations that cqspi_set_protocol() was never expected to handle
> correctly - in particuar all non-DTR operations with command or address
> buswidth > 1. For DTR, all operations except for 8-8-8 would fail, as
> cqspi_set_protocol() returns -EINVAL.
> 
> In non-DTR mode, this resulted in data corruption for SPI-NOR flashes that
> support such operations. As a minimal fix that can be backported to stable
> kernels, simply disallow the unsupported operations again to avoid this
> issue.
> 
> Fixes: a314f6367787 ("mtd: spi-nor: Convert cadence-quadspi to use spi-mem framework")
> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>

I suppose it is too late now since the patch is already applied. But 
FWIW,

Reviewed-by: Pratyush Yadav <p.yadav@ti.com>

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.