From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0AEA1F8914; Tue, 7 Jan 2025 21:30:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736285412; cv=none; b=cyvEi+udDli8G5DO/bvda8+lIbIcCTsqzISVDdRe37uLVsJ7a1lFfhhre1yXGkCev0dGD/n2vyF7ZxQp6dklo8B60PdwpVWiU81zJ/Kw2tPLGCOoWYMI4q3gQqrLH5+YpILqP9kuasCKQp0IlRAEn6i7mvCIJB06vDdaq1U3qL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736285412; c=relaxed/simple; bh=ac6y/Dz/2pY1MzjvhpThvPDoZJ/PH81sANKCYDwfnFc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BeXgmRpnJv3FBZnylru/zGvIjdkwG1jRXg7ZbX4C3fUOWiQK/y09Gj5A+FR2N7Ado6Jo5Kg0+g1DLXXVA99vsWk+zBZtEALC6s4v+xOblvviPIuw+v3U38bnCYXbLpQQoUtgRll3sS+lqKvFx+RfynQTB4ZVBZibo4zH8JcnBys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tZ96DGpV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tZ96DGpV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5C48C4CEE4; Tue, 7 Jan 2025 21:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736285411; bh=ac6y/Dz/2pY1MzjvhpThvPDoZJ/PH81sANKCYDwfnFc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=tZ96DGpVyYejpIudGq3GbE5JSUKls64N4vnwevP+GWRZCXZfEDDhdheH5Qq822oFv 3zK6zH+Q8tJfKpnp0Rr2eJA6D/sEcwFLtD+rDO1s4NAjatJR+Zb4pRSXa7gHgXOBNe nBvMN8yGmejJ3U5KM4bgI/NpqlPbsFcGC6g/xVrEM4MKMXtUuYVZuLVljT+8OYnaM0 62y1l4/iO7Mq514KHp/heaotnjhkoHzy9UrkFcs/N6I8A3VphQBAN2r9IvcO4nRuOe kB6KdeV7XeK5kBv0lA5ZZgjV+B/Hubzvxj3awQXtQ/X6moTNbdiPHvWTWJJARwvDYS cY+n2QuZKToEA== Message-ID: <9ef3daa8-cdb1-49f2-8d19-a72d6210ff3a@kernel.org> Date: Tue, 7 Jan 2025 23:30:18 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] dmaengine: qcom: bam_dma: Avoid writing unavailable register To: Md Sadre Alam , vkoul@kernel.org, linux-arm-msm@vger.kernel.org, dmaengine@vger.kernel.org Cc: quic_mmanikan@quicinc.com, quic_srichara@quicinc.com, quic_varada@quicinc.com, robin.murphy@arm.com, u.kleine-koenig@baylibre.com, martin.petersen@oracle.com, fenghua.yu@intel.com, av2082000@gmail.com, linux-kernel@vger.kernel.org References: <20241220094203.3510335-1-quic_mdalam@quicinc.com> Content-Language: en-US From: Georgi Djakov In-Reply-To: <20241220094203.3510335-1-quic_mdalam@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 20.12.24 11:42, Md Sadre Alam wrote: > Avoid writing unavailable register in BAM-Lite mode. > BAM_DESC_CNT_TRSHLD register is unavailable in BAM-Lite > mode. Its only available in BAM-NDP mode. So only write > this register for clients who is using BAM-NDP. > > Signed-off-by: Md Sadre Alam > --- My Dragonboard db845c fails to boot on recent linux-next releases and git bisect points to this patch. It boots again when it's reverted. [..] > > bchan->reconfigure = 0; > @@ -1192,10 +1199,11 @@ static int bam_init(struct bam_device *bdev) > u32 val; > > /* read revision and configuration information */ > - if (!bdev->num_ees) { > - val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)); > + val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)); > + if (!bdev->num_ees) > bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK; > - } > + > + bdev->bam_revision = val & REVISION_MASK; The problem seems to occur when we try to read the revision for the slimbus bam instance at 0x17184000 (which has "qcom,num-ees = <2>;"). Thanks, Georgi