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From:   Colin Ian King <colin.king@canonical.com>
To:     Biju Das <biju.das.jz@bp.renesas.com>
Cc:     Liam Girdwood <lgirdwood@gmail.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        alsa-devel@alsa-project.org
Subject: re: ASoC: sh: Add RZ/G2L SSIF-2 driver
Message-ID: <962029d0-d001-f85c-1676-262372faeb34@canonical.com>
Date:   Mon, 16 Aug 2021 17:43:05 +0100
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Hi,

Static analysis on linux-next with Coverity has detected an issue in
rz_ssi_stop, sound/soc/sh/rz-ssi.c with the following commit:

commit 03e786bd43410fa93e5d2459f7a43e90ff0ae801
Author: Biju Das <biju.das.jz@bp.renesas.com>
Date:   Fri Aug 13 10:11:54 2021 +0100

    ASoC: sh: Add RZ/G2L SSIF-2 driver


The analysis is as follows:

367
368        /* Wait for idle */
369        timeout = 100;
370        while (--timeout) {

Wrong operator used (CONSTANT_EXPRESSION_RESULT)

operator_confusion: rz_ssi_reg_readl(ssi, 4) | (33554432UL /* 1UL << 25
*/) is always 1/true regardless of the values of its operand. This
occurs as the logical operand of if.

371                if (rz_ssi_reg_readl(ssi, SSISR) | SSISR_IIRQ)
372                        break;
373                udelay(1);
374        }

I suspect the & operator was intended to mask the specific bit. However
I'm not sure if the intent is to detect if the SSISR_IIRQ bit should be
zero or one at the point where the break should occur, hence I'm
reporting this issue.

Colin