Messages in this thread | | | Date | Mon, 28 Jan 2008 13:04:51 +0000 | From | richard kennedy <> | Subject | Re: [rfc] exposing MMR's of on-chip peripherals for debugging purposes |
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Mike Frysinger wrote: > On Jan 28, 2008 5:40 AM, Bryan Wu <bryan.wu@analog.com> wrote: >> On Mon, 2008-01-28 at 05:16 -0500, Mike Frysinger wrote: >>> the trouble is that this file currently weighs in at ~1.8 megs. this >>> is because it contains all the information for all Blackfin processors >>> we support (which currently, is about ~23 variants). it's only going >>> to get bigger as we support more. Bryan cringes at the thought of >>> submitting it to LKML :). so i'm fishing around for alternatives ... >>> the code was originally developed against 2.6.21, so UIO was not a >>> possibility. i'm still not sure if it is ... i'd have to research it >>> a bit more and play with things. >> The main reason I am not willing to submit this to mainline is the file >> size. It's almost the biggest file in the kernel source. And it will be >> bigger and bigger when more and more new Blackfin processors supported >> by Linux kernel. > > a quick check of current git shows it is significantly larger than any other ;) > >> My suggestion is: >> Or more deeper thought: >> - we don't need all the MMR setup at the same time for debugging. for example, maybe for some developer, he/she only needs one driver MMR for debugging such as watchdog/usb/spi/i2c .... > > splitting things up doesnt really address the original issue: there's > a lot of info here to be kept in the kernel > >> - How about split the debug MMR table to each drivers or processors? >> - watchdog driver implements a debug FS interface for debugging watchdog MMR and other drivers implement their own things. > > this had been mentioned before as a possibility but shot down. you do > not want to tie the creation of these debug files to anything as the > prevents independent development of any other drivers/application that > use the same peripheral. > -mike
Hi Mike, there is a lot of duplication in your file, but you could slim it down a bit if thats the only objection.
for instance all the COUNTER element addresses have the same offsets from CNT_CONFIG
CNT_IMASK = CNT_CONFIG + 4 CNT_STATUS = CNT_CONFIG + 8 CNT_COMMAND = CNT_CONFIG + 12 CNT_DEBOUNCE = CNT_CONFIG + 16 CNT_COUNTER = CNT_CONFIG + 20 CNT_MAX = CNT_CONFIG + 24 CNT_MIN = CNT_CONFIG + 28
so you could have a simple function to create all the COUNTER elements from a given base address, then each variant only needs call that saving you lots of LOC.
something like :-
make_counter_dir(top, base ) { parent = debugfs_create_dir("Counter", top); debugfs_create_x16("CNT_COMMAND", 0600, parent, base+12); debugfs_create_x16("CNT_CONFIG", 0600, parent, base); ... }
Hopefully all the other sections have similar levels of duplication, but I haven't checked.
Cheers Richard
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