From patchwork Wed Sep 12 10:57:59 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shubhrajyoti Datta X-Patchwork-Id: 1442611 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (unknown [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id D51F54025E for ; Wed, 12 Sep 2012 11:11:24 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TBkgh-0000P1-US; Wed, 12 Sep 2012 11:00:57 +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 1TBked-00083Z-7H for linux-arm-kernel@lists.infradead.org; Wed, 12 Sep 2012 10:58:49 +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 q8CAwRWF005860; Wed, 12 Sep 2012 05:58:28 -0500 Received: from DBDE70.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id q8CAwNX2018579; Wed, 12 Sep 2012 16:28:26 +0530 (IST) Received: from dbdp33.itg.ti.com (172.24.170.252) by dbde70.ent.ti.com (172.24.170.148) with Microsoft SMTP Server id 14.1.323.3; Wed, 12 Sep 2012 16:28:24 +0530 Received: from ula0393217.india.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp33.itg.ti.com (8.13.8/8.13.8) with ESMTP id q8CAwJZC009194; Wed, 12 Sep 2012 16:28:24 +0530 From: Shubhrajyoti D To: Subject: [PATCHv8 05/22] i2c: omap: simplify omap_i2c_ack_stat() Date: Wed, 12 Sep 2012 16:27:59 +0530 Message-ID: <1347447496-16793-6-git-send-email-shubhrajyoti@ti.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1347447496-16793-1-git-send-email-shubhrajyoti@ti.com> References: <1347447496-16793-1-git-send-email-shubhrajyoti@ti.com> MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -7.3 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.3 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 SPF_PASS SPF: sender matches SPF record -0.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -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 30ea63c..f24eae9 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -731,7 +731,7 @@ 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; } @@ -792,10 +792,11 @@ 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; } @@ -842,8 +843,8 @@ 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; } @@ -890,8 +891,8 @@ 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; }