From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Mon, 22 Sep 2014 13:04:55 +0200 Subject: [PATCH] i2c: axxia: Add I2C driver for AXM55xx In-Reply-To: References: <1408967482-17723-1-git-send-email-anders.berg@avagotech.com> <20140920121242.GA3833@katana> <20140922095939.GB1406@katana> Message-ID: <20140922110455.GA1463@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > >> >> + if (msg->len == 0 || msg->len > 255) > >> >> + return -EINVAL; > >> > > >> > Ouch, really? Maybe we should warn the user here. > >> > >> Yeah, the transfer length register limits the length to 255. I'll add > >> a warning here. > > > > Please also add this information to the Kconfig description and > > somewhere at the top of the source file. This is an important flaw which > > people should easily find out about. > > > > You are referring to the "len <= 255" restriction being the flaw here, > right? I'll add a note to Kconfig and the driver about that. Yes, I meant that. I just remembered we should do something else: Remove I2C_FUNC_I2C (because it cannot do endless transfers) from functionality and simply use I2C_FUNC_SMBUS_I2C_BLOCK which does I2C like transfers with the SMBus Limit of 32 bytes. It seems PMBus allows for 255 byte which this HW could support, yet I don't recall we have support for that size currently. > The other part of the condition (msg->len == 0) should actually go > away. The controller can do zero-length-data transfers. I'll fix that > for next round. Great! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: