From patchwork Sat Sep 12 21:07:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 11772071 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 971641580 for ; Sat, 12 Sep 2020 21:08:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B582207FB for ; Sat, 12 Sep 2020 21:08:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="n+aUgG/R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725956AbgILVIr (ORCPT ); Sat, 12 Sep 2020 17:08:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725918AbgILVIT (ORCPT ); Sat, 12 Sep 2020 17:08:19 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD839C061573 for ; Sat, 12 Sep 2020 14:08:17 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id s65so7630532pgb.0 for ; Sat, 12 Sep 2020 14:08:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=hkdmHZJNcU+7N2ujCFsZPcv/unm2Wh+tx7Rkz6iTuF0=; b=n+aUgG/RdRP686huE3p5uz0c0aoEJ5mJl26a3jq1Q33zTy4H3FB4bwCKZF5u6wdJgO zz7he6IVgc5ADax0REzyDDWXGHQF2QSqLHbsS/vPCNZ+dpOV+5WeTNMXJbt0lS0nWWgE NCFVo40UENKFCM99tOaWb/pynEAIUh28jH3kU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=hkdmHZJNcU+7N2ujCFsZPcv/unm2Wh+tx7Rkz6iTuF0=; b=sW6rOQ3Wr93kHs74wo5is4mg84TccKA4PhXlg282S8av27mTO/9c3x4PV8M2ozzQ04 7lZmMzQ4eQHx0eoW4SYnwR1LeKpVTfrraZn+z9S14j4zUtUG1D3UFsCtBZgOFreX8ulQ jjLe/op1tUW55nI5+WUiRa1iqCqor9pIvzlYemi7zL5RW742ebIn7hw/1nGdZDIFi5LC /xCBqCnWxzJtPiv4lsXOhEaLgawMrQMxPD7M+8o25wBFLL98ZOq0kki/Q+8CFL9HU3V0 Ni+dAbYYNKKr0auYbzaKB1irrfwMfhMa3d6hHgHTFYKYKpdBbyGPz27PK7EKkEvZf8sm D2vA== X-Gm-Message-State: AOAM530jquD1LtFZ/1K4L7+ugSJTc1zSJhfmLvxZrdPhY92nKMluMbW+ qwVbKK4pR7ELQxIlpapOozJBp9coguT+pQ== X-Google-Smtp-Source: ABdhPJz22rwSO4QjmaRCwJE0H6ZOVP9TpnHWSmb2igzOtjxEis+mUFk/egFXQj1mz3ang7qDeLgZ7g== X-Received: by 2002:a63:29c7:: with SMTP id p190mr5938653pgp.292.1599944897297; Sat, 12 Sep 2020 14:08:17 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:42b0:34ff:fe3d:58e6]) by smtp.gmail.com with ESMTPSA id e10sm3369020pgb.45.2020.09.12.14.08.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Sep 2020 14:08:16 -0700 (PDT) From: Douglas Anderson To: Mark Brown Cc: Akash Asthana , swboyd@chromium.org, Douglas Anderson , Andy Gross , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org Subject: [PATCH 1/3] spi: spi-geni-qcom: Use the FIFO even more Date: Sat, 12 Sep 2020 14:07:59 -0700 Message-Id: <20200912140730.1.Ie67fa32009b94702d56232c064f1d89065ee8836@changeid> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org In commit 902481a78ee4 ("spi: spi-geni-qcom: Actually use our FIFO") I explained that the maximum size we could program the FIFO was "mas->tx_fifo_depth - 3" but that I chose "mas->tx_fifo_depth()" because I was worried about decreased bandwidth. Since that time: * All the interconnect patches have landed, making things run at the proper speed. * I've done more measurements. This lets me confirm that there's really no downside of using the FIFO more. Specifically I did "flashrom -p ec -r /tmp/foo.bin" on a Chromebook and averaged over several runs. Before: It took 6.66 seconds and 59669 interrupts fired. After: It took 6.66 seconds and 47992 interrupts fired. Signed-off-by: Douglas Anderson Reviewed-by: Bjorn Andersson Reviewed-by: Akash Asthana --- drivers/spi/spi-geni-qcom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 0dc3f4c55b0b..7f0bf0dec466 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -308,7 +308,7 @@ static int spi_geni_init(struct spi_geni_master *mas) * Hardware programming guide suggests to configure * RX FIFO RFR level to fifo_depth-2. */ - geni_se_init(se, mas->tx_fifo_depth / 2, mas->tx_fifo_depth - 2); + geni_se_init(se, mas->tx_fifo_depth - 3, mas->tx_fifo_depth - 2); /* Transmit an entire FIFO worth of data per IRQ */ mas->tx_wm = 1; ver = geni_se_get_qup_hw_version(se);