From patchwork Wed Feb 4 11:31:50 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 436241 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 48047140272; Wed, 4 Feb 2015 22:31:26 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1YIyB0-0007bz-0Y; Wed, 04 Feb 2015 11:31:22 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1YIyAs-0007bF-RT for kernel-team@lists.ubuntu.com; Wed, 04 Feb 2015 11:31:14 +0000 Received: from av-217-129-142-138.netvisao.pt ([217.129.142.138] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1YIyAs-0003TU-HB; Wed, 04 Feb 2015 11:31:14 +0000 From: Luis Henriques To: Axel Lin Subject: [3.16.y-ckt stable] Patch "spi: dw: Fix detecting FIFO depth" has been added to staging queue Date: Wed, 4 Feb 2015 11:31:50 +0000 Message-Id: <1423049510-32244-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 X-Extended-Stable: 3.16 Cc: kernel-team@lists.ubuntu.com, Mark Brown X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled spi: dw: Fix detecting FIFO depth to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt6. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From dd3f32c29e5509c31e214f8e2aea596dee2200d3 Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Mon, 5 Jan 2015 09:32:56 +0800 Subject: spi: dw: Fix detecting FIFO depth commit d297933cc7fcfbaaf2d37570baac73287bf0357d upstream. Current code tries to find the highest valid fifo depth by checking the value it wrote to DW_SPI_TXFLTR. There are a few problems in current code: 1) There is an off-by-one in dws->fifo_len setting because it assumes the latest register write fails so the latest valid value should be fifo - 1. 2) We know the depth could be from 2 to 256 from HW spec, so it is not necessary to test fifo == 257. In the case fifo is 257, it means the latest valid setting is fifo = 256. So after the for loop iteration, we should check fifo == 2 case instead of fifo == 257 if detecting the FIFO depth fails. This patch fixes above issues. Signed-off-by: Axel Lin Reviewed-and-tested-by: Andy Shevchenko Signed-off-by: Mark Brown Signed-off-by: Luis Henriques --- drivers/spi/spi-dw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.1.4 diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 080e0a343675..32a3718cc5b4 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -622,13 +622,13 @@ static void spi_hw_init(struct dw_spi *dws) */ if (!dws->fifo_len) { u32 fifo; - for (fifo = 2; fifo <= 257; fifo++) { + for (fifo = 2; fifo <= 256; fifo++) { dw_writew(dws, DW_SPI_TXFLTR, fifo); if (fifo != dw_readw(dws, DW_SPI_TXFLTR)) break; } - dws->fifo_len = (fifo == 257) ? 0 : fifo; + dws->fifo_len = (fifo == 2) ? 0 : fifo - 1; dw_writew(dws, DW_SPI_TXFLTR, 0); } }