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 A4B2612B73; Mon, 10 Mar 2025 21:01:03 +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=1741640463; cv=none; b=GpfhwkIhT9HzIR1ziF38bhC9GbL3joQ5p/YtVzS9YH69BLh+KW+XvXe7z9zrB5h+cFQFLuhvBQf+RbBhfCDWOsYY3hqP8p/2kK9YKH6zhWusJigNBxfT4wVMrk4AyJ0OkcPuNg6GuV4ooG7AvFvH4Oy3qOOXXHT5817E8UuabjQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741640463; c=relaxed/simple; bh=aYyGi+0GlhtZZOl3eElkEgro/Og6UgEBW7ME0Eh2cEM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Uj1WkTgSopApKZtTKGLls2ma+G9zFYIvmn5sIvn8bvFJTEKyAEskUTKCGc2pm+34h+iabTmPKxqWnmdzQq9UUoT+/r+9PB+BmOO1q2G87jFef1dovRawFzPvBr1cnfd1SNgzejaO82mtpEvxoEx+cj128uiixj5Azyg+PoibC3k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XELG8I6W; 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="XELG8I6W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CE6AC4CEE5; Mon, 10 Mar 2025 21:01:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741640463; bh=aYyGi+0GlhtZZOl3eElkEgro/Og6UgEBW7ME0Eh2cEM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XELG8I6WYICbM6YDswWTIzR5vBY0ZCdCcGJ/XwRd+rPF8jWKv8h3HR7gxrqFV55Yk YC03rspukIbY7kdASAul32qn3tTTF0Mjsk4YyEhIb3u5/Qj1XV8c+Zcm0FFT2h6v/m F+zkgxIJhbNnd1atUL3+ZMTBsK1wGd1gj7eVnMIfItWqcZQxPHdLUiPB76A4Z3cCow IF6tot8i/DiR7HlFaN9aZMA18vcatU2dTOp5YxckUak3MYgFIzXJtGfVYF6T2k2P02 /qA3Twqr+moDiV/Zm01s5J3HOrF4lAXYPAyy3NYPcJQWX3oaLIFX74c7Yw+/KrdG1v Dwfdi1Ujv4h8A== Date: Tue, 11 Mar 2025 02:30:59 +0530 From: Vinod Koul To: Jyothi Kumar Seerapu Cc: Andi Shyti , Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , linux-arm-msm@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, quic_msavaliy@quicinc.com, quic_vtanuku@quicinc.com Subject: Re: [PATCH v5 RESEND 1/2] dmaengine: qcom: gpi: Add GPI Block event interrupt support Message-ID: References: <20250212120536.28879-1-quic_jseerapu@quicinc.com> <20250212120536.28879-2-quic_jseerapu@quicinc.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250212120536.28879-2-quic_jseerapu@quicinc.com> On 12-02-25, 17:35, Jyothi Kumar Seerapu wrote: > GSI hardware generates an interrupt for each transfer completion. > For multiple messages within a single transfer, this results in > N interrupts for N messages, leading to significant software > interrupt latency. > > To mitigate this latency, utilize Block Event Interrupt (BEI) mechanism. > Enabling BEI instructs the GSI hardware to prevent interrupt generation > and BEI is disabled when an interrupt is necessary. > > When using BEI, consider splitting a single multi-message transfer into > chunks of 8 messages internally and so interrupts are not expected for > the first 7 message completions, only the last message triggers > an interrupt, indicating the completion of 8 messages. > > This BEI mechanism enhances overall transfer efficiency. That sounds good but I dont like the idea that we add a custom interface for this. Please use DMA_PREP_INTERRUPT instead. Adding this flag should trigger N interrupts, absence of this should lead to Block events only -- ~Vinod