From patchwork Thu Jul 19 14:37:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shubhrajyoti Datta X-Patchwork-Id: 1217601 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id F2FEEDF24C for ; Thu, 19 Jul 2012 14:50:23 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Srruk-00047W-Gk; Thu, 19 Jul 2012 14:41:14 +0000 Received: from comal.ext.ti.com ([198.47.26.152]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SrrsZ-0003zk-J1 for linux-arm-kernel@lists.infradead.org; Thu, 19 Jul 2012 14:39:02 +0000 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id q6JEcRse031796; Thu, 19 Jul 2012 09:38:28 -0500 Received: from DBDE71.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id q6JEcPIe003813; Thu, 19 Jul 2012 20:08:27 +0530 (IST) Received: from dbdp32.itg.ti.com (172.24.170.251) by DBDE71.ent.ti.com (172.24.170.149) with Microsoft SMTP Server id 14.1.323.3; Thu, 19 Jul 2012 20:08:25 +0530 Received: from ula0393217.india.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp32.itg.ti.com (8.13.8/8.13.8) with ESMTP id q6JEcLWM030469; Thu, 19 Jul 2012 20:08:25 +0530 From: Shubhrajyoti D To: Subject: [PATCHv5 05/18] i2c: omap: simplify omap_i2c_ack_stat() Date: Thu, 19 Jul 2012 20:07:55 +0530 Message-ID: <1342708688-2342-6-git-send-email-shubhrajyoti@ti.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1342708688-2342-1-git-send-email-shubhrajyoti@ti.com> References: <1342708688-2342-1-git-send-email-shubhrajyoti@ti.com> MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -6.9 (------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-6.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [198.47.26.152 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: tony@atomide.com, w.sang@pengutronix.de, Felipe Balbi , linux-i2c@vger.kernel.org, ben-linux@fluff.org, Shubhrajyoti D , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Felipe Balbi stat & BIT(1) is the same as BIT(1), so let's simplify things a bit by removing "stat &" from all omap_i2c_ack_stat() calls. Code snippet (extremely simplified): if (stat & NACK) { ... omap_i2c_ack_stat(dev, stat & NACK); } if (stat & RDR) { ... omap_i2c_ack_stat(dev, stat & RDR); } and so on. The tricky place is only WRT errata handling, for example: if (*stat & (NACK | AL)) { omap_i2c_ack_stat(dev, *stat & (XRDY | XDR)); ... } but in this case, the errata says we must clear XRDY and XDR if that errata triggers, so if they just got enabled or not, it doesn't matter. Another tricky place is RDR | RRDY (likewise for XDR | XRDY): if (stat & (RDR | RRDY)) { ... omap_i2c_ack_stat(dev, stat & (RDR | RRDY)); } again here there will be no issues because those IRQs never fire simultaneously and one will only after after we have handled the previous, that's because the same FIFO is used anyway and we won't shift data into FIFO until we tell the IP "hey, I'm done with the FIFO, you can shift more data" Signed-off-by: Felipe Balbi Reviewed-by : Santosh Shilimkar [Added the explaination from the discurssion to the commit logs] Signed-off-by: Shubhrajyoti D --- drivers/i2c/busses/i2c-omap.c | 19 ++++++++++--------- 1 files changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 323d52e..940ba64 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -728,7 +728,7 @@ static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err) while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) { if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { - omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY | + omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); return -ETIMEDOUT; } @@ -789,10 +789,11 @@ complete: */ if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { - omap_i2c_ack_stat(dev, stat & - (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | - OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR | - OMAP_I2C_STAT_ARDY)); + omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY | + OMAP_I2C_STAT_RDR | + OMAP_I2C_STAT_XRDY | + OMAP_I2C_STAT_XDR | + OMAP_I2C_STAT_ARDY)); omap_i2c_complete_cmd(dev, err); return IRQ_HANDLED; } @@ -839,8 +840,8 @@ complete: } } } - omap_i2c_ack_stat(dev, - stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)); + omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY | + OMAP_I2C_STAT_RDR)); continue; } @@ -887,8 +888,8 @@ complete: omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); } - omap_i2c_ack_stat(dev, - stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); + omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY | + OMAP_I2C_STAT_XDR)); continue; }