From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamil Debski Subject: RE: [PATCH] [media] s5p-mfc: add init buffer cmd to MFCV6 Date: Fri, 07 Mar 2014 13:48:34 +0100 Message-ID: <19dc01cf3a03$8dba8d80$a92fa880$%debski@samsung.com> References: <1394181090-16446-1-git-send-email-arun.kk@samsung.com> <53199175.6030606@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mailout4.w1.samsung.com ([210.118.77.14]:29539 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751669AbaCGMsi (ORCPT ); Fri, 7 Mar 2014 07:48:38 -0500 In-reply-to: Content-language: pl Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: 'Arun Kumar K' , Sylwester Nawrocki Cc: "'avnd.kiran'" , 'LMML' , 'linux-samsung-soc' , 'Pawel Osciak' Hi Arun, > From: Arun Kumar K [mailto:arunkk.samsung@gmail.com] > Sent: Friday, March 07, 2014 12:10 PM > > Hi Sylwester, > > On Fri, Mar 7, 2014 at 2:59 PM, Sylwester Nawrocki > wrote: > > Hi, > > > > On 07/03/14 09:31, Arun Kumar K wrote: > >> From: avnd kiran > >> > >> Latest MFC v6 firmware requires tile mode and loop filter setting to > >> be done as part of Init buffer command, in sync with v7. So, move > >> these settings out of decode options reg. > >> Also, make this register definition applicable from v6 onwards. > >> > >> Signed-off-by: avnd kiran > >> Signed-off-by: Arun Kumar K > > > > Will the driver also work with older version of the firmware after > > this change ? If not, shouldn't things like this be done depending on > > what firmware version is loaded ? > > > > The original code was for the initial version of v6 firmware. > After that the v6 firmware has got many fixes and updates which also > got updated in the products running the same. > As such there are no official multiple versions of v6 firmware, but > only fixes / updates to older version. I will update the s5p-mfc-v6.fw > in the linux-firmware also with the newer version. Hope that will be > fine. Unfortunately, I share the same concerns as Sylwester. We have two problems: 1) new kernel + old firmware In this case, someone will update the kernel and find out that video decoding is not working. An assumption that I think is common, is that updating the kernel should not break anything. If it was working with the previous version it should work with the next. The solution I can suggest is that a check which firmware version is used has to be implemented. Maybe you can use the date of firmware to do this check? 2) old kernel + new firmware I see no clear solution to this problem. If the kernel is old and the firmware is behaving differently, the video decoding will not work. I can guess that this case would be less common, but still a person can update the firmware and leave the old kernel. Changing the firmware can be done by replacing a single file. In addition to the above, you need to clearly specify in the linux-firmware.git what is going on. A readme file is a must. Maybe a second v6 firmware file should be included? Best wishes, -- Kamil Debski Samsung R&D Institute Poland