From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Sverdlin Subject: Re: [RFC PATCH] i2c: busses: i2c-omap: Increase timeout for i2c interrupt Date: Fri, 10 Jul 2015 15:26:01 +0200 Message-ID: <559FC7E9.1060003@nokia.com> References: <1436504994-31137-1-git-send-email-vigneshr@ti.com> <559F8670.2060305@nokia.com> <20150710090909.GF1528@katana> <559FC5D7.3000108@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <559FC5D7.3000108-l0cyMroinI0@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ext Vignesh R , Wolfram Sang , Felipe Balbi Cc: Tony Lindgren , linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hi! On 10/07/15 15:17, ext Vignesh R wrote: >>> I would propose you to throw away spinlocks. Convert threaded IRQ to >>> >> just one hardirq handler. And continue debugging. You will reduce the >>> >> load of the system with the above measures, maybe it will not happen >>> >> any more, maybe you'll figure out that problem is somewhere else. >> > >> > Or this. > I am not convinced with moving entire code at hardirq context. I believe > its better to keep hardirq as small as possible. How deep is the controller's FIFO? 1 byte? 2 bytes? Other drivers can perfectly fill next byte in hardirq handler. If you need to do 10 opcodes more in hardirq handler, it's much better for the whole system than to trigger scheduler and thread and and and just because of these 10 opcodes. -- Best regards, Alexander Sverdlin.