From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934237AbcI0T2H (ORCPT ); Tue, 27 Sep 2016 15:28:07 -0400 Received: from smtp.domeneshop.no ([194.63.252.55]:54343 "EHLO smtp.domeneshop.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932573AbcI0T16 (ORCPT ); Tue, 27 Sep 2016 15:27:58 -0400 Subject: Re: [PATCH v2 3/8] i2c: bcm2835: Use ratelimited logging on transfer errors To: Martin Sperl References: <1474977426-3272-1-git-send-email-noralf@tronnes.org> <1474977426-3272-4-git-send-email-noralf@tronnes.org> <74D9ED33-1B99-4ED6-88B5-879950D160C8@martin.sperl.org> Cc: wsa@the-dreams.de, swarren@wwwdotorg.org, eric@anholt.net, linux-rpi-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= Message-ID: <66be95f1-3ed7-7abc-3def-b10582d609ea@tronnes.org> Date: Tue, 27 Sep 2016 21:27:54 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <74D9ED33-1B99-4ED6-88B5-879950D160C8@martin.sperl.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Den 27.09.2016 15:01, skrev Martin Sperl: >> On 27 Sep 2016, at 13:57, Noralf Trønnes wrote: >> >> Writing to an AT24C32 generates on average 2x i2c transfer errors per >> 32-byte page write. Which amounts to a lot for a 4k write. This is due >> to the fact that the chip doesn't respond during it's internal write >> cycle when the at24 driver tries and retries the next write. >> Reduce this flooding of the log by using dev_err_ratelimited(). >> >> Signed-off-by: Noralf Trønnes >> Reviewed-by: Eric Anholt >> --- >> drivers/i2c/busses/i2c-bcm2835.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c >> index df036ed..370a322 100644 >> --- a/drivers/i2c/busses/i2c-bcm2835.c >> +++ b/drivers/i2c/busses/i2c-bcm2835.c >> @@ -207,7 +207,8 @@ static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev, >> (msg->flags & I2C_M_IGNORE_NAK)) >> return 0; >> >> - dev_err(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err); >> + dev_err_ratelimited(i2c_dev->dev, "i2c transfer failed: %x\n", >> + i2c_dev->msg_err); > Do we really need this error message at all? > > Maybe just remove it instead, because error messages during > "normal"/successfull operations of at24 seems strange. > > Or make it a debug message instead. I have looked through 64 i2c bus drivers, 8 use dev_err and 2 use dev_warn on transfer errors (not timeouts). Several use dev_dbg. I'll change it to dev_dbg instead. Thanks. Noralf.