From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Rubinstein Subject: Re: Intel ICHx bus driver Date: Mon, 22 Feb 2010 18:12:41 +0200 Message-ID: References: <20100128085904.4e202de1@hyperion.delvare> <20100128105340.41aecf64@hyperion.delvare> <20100219105841.2bd8b16c@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100219105841.2bd8b16c-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hi Jean/i2c guys, I'm having hard time to send straight I2C transaction of arbitrary leng= th. I use i2c_smbus_write_i2c_block_data(fd, buf[0], datac - 1, &buf[1]); from user-space to send the aforementioned transaction, but I get operation not permitted as a result. I tried to understand what's going on in the driver and found out that timeout occurs. As a consequence, I'd like to get something clear to me: Since ICH9 supports 32-Byte Buffer (E32B) and according to the data sheet the DS bit of the HST_STS is meaningless when E32B is enabled and it's (E32B) enabled by the i801 driver. On the other hand, in i801_check_pre called (from i801_block_transaction_by_block) the macro STATUS_FLAGS verifies the DS bit (designated as SMBHSTSTS_BYTE_DONE in the code). Looking at the previous version of the driver, like in 2.5.25 there was a mask 0x1f but it has gone since. Is this behavior correct? And another question related. Have you/anyone tried to output I2C write transaction of arbitrary length, i.e. DATA0 is not sent on the bus, from ICH9? Thank you in advance, =46elix R. On Fri, Feb 19, 2010 at 11:58 AM, Jean Delvare wro= te: > Hi Felix, > > On Fri, 19 Feb 2010 09:10:03 +0200, Felix Rubinstein wrote: >> Does ICHx support straight I2C read of arbitrary length, i.e. withou= t doing >> write first? > > No, it doesn't. The only straight read lengths supported are 0 byte > (SMBus quick command) and 1 byte (SMBus receive byte). > > -- > Jean Delvare > http://khali.linux-fr.org/wishlist.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" = in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html >