From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Simek Subject: Re: [RFC PATCH] drivers: ata: Read Rx water mark value from device-tree Date: Wed, 2 Mar 2016 12:51:44 +0100 Message-ID: <56D6D3D0.9030408@xilinx.com> References: <1455974302-7082-1-git-send-email-anuragku@xilinx.com> <3012728.7zDNPtQ7kR@wuerfel> <56D6B217.2000701@xilinx.com> <1798710.nJonRpmlxx@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1798710.nJonRpmlxx@wuerfel> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnd Bergmann , Michal Simek Cc: Anurag Kumar Vulisha , Rob Herring , =?UTF-8?Q?S=c3=b6ren_Brinkmann?= , "pawel.moll-5wv7dgnIgG8@public.gmane.org" , "mark.rutland-5wv7dgnIgG8@public.gmane.org" , "ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org" , "galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org" , "tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-ide-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Anirudha Sarangi , Srikanth Vemula , Punnaiah Choudary Kalluri List-Id: linux-ide@vger.kernel.org On 2.3.2016 12:42, Arnd Bergmann wrote: > On Wednesday 02 March 2016 10:27:51 Michal Simek wrote: >> >> No problem with default value in driver. Something has to be setup. >> Reset value based on reg spec I was checking is 0x20. Based on our >> testing we saw some issues that's why 0x40 was setup as default value. >> There is a need to be able to configure this value for example for >> testing different values that's why I think module parameter should be >> the right way to go. > > I don't object to the module parameter, but I don't understand how important > that kind of testing is to normal users. Who would set it, aside from > the person writing that driver to come up with the correct default? > >> If this should be DT parameters there should be different ceva IP which >> allows different fifo size and different watermark level to be setup by >> user. >> >> What do you think? Does it sound reasonable. > > Having a property for the actual hardware fifo size once you get > different implementations seems like the correct approach, but it's > moot as long as all implementations are hardwired to 128 entries. yep right now and we don't know what can happen in future. I just wanted to point to example where this property can be specified or wired to particular compatible string. Anurag: Please make it as module parameter instead of DT parameter. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html