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 54A00DF40 for ; Mon, 15 May 2023 16:38:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC6D3C433D2; Mon, 15 May 2023 16:38:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684168713; bh=G7W4eoBKhhIOADPWKjo/ZrM8cFKiCmHtTGPXaeBZKcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gc09sUuoA0YR2Jxm4L0idFZVS5XMWQU4sDYkpuRtdt6Eq4XspNa1T3aIgjrU+nL7D XTKRHD0vd/X9DfStqXLFwMiex7LMgm9h6V7Jy5nxGB4DqjccJ1sJfC/ChjI4FdyBRc jgj6n1sDwv1u2NQGRUeCr7RL4TY7vCsndafM9uns= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Reid Tonking , Vignesh Raghavendra , Tony Lindgren , Wolfram Sang Subject: [PATCH 4.19 018/191] i2c: omap: Fix standard mode false ACK readings Date: Mon, 15 May 2023 18:24:15 +0200 Message-Id: <20230515161707.860435453@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161707.203549282@linuxfoundation.org> References: <20230515161707.203549282@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Reid Tonking commit c770657bd2611b077ec1e7b1fe6aa92f249399bd upstream. Using standard mode, rare false ACK responses were appearing with i2cdetect tool. This was happening due to NACK interrupt triggering ISR thread before register access interrupt was ready. Removing the NACK interrupt's ability to trigger ISR thread lets register access ready interrupt do this instead. Cc: # v3.7+ Fixes: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support") Signed-off-by: Reid Tonking Acked-by: Vignesh Raghavendra Reviewed-by: Tony Lindgren Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-omap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -1027,7 +1027,7 @@ omap_i2c_isr(int irq, void *dev_id) u16 stat; stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); - mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); + mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK; if (stat & mask) ret = IRQ_WAKE_THREAD;