Messages in this thread |  | | | From | Bartlomiej Zolnierkiewicz <> | | Subject | Re: [PATCH 00/18] misc generic ide stuff | | Date | Sat, 14 Jun 2008 19:29:00 +0200 |
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Hi,
On Thursday 12 June 2008, Borislav Petkov wrote: > Hi Bart, > > here are some generic ide conversion patches. The first 12 are what i thought > you suggested :) concerning prepping the ide-cd code for the generic layer. The > remaining 6 are what i've done so far wrt removing ide_atapi_pc from the ide > drivers. It is obvious that this is not trivial and I basically tiptoe around the
Thanks.
I applied patches #1-2, #5-12 and #14-15.
I skipped patches #3-4, #13 and #16-18 for now (more details in replies to corresponding mails).
> landmines in the IRQ handler and request issue paths :). This raises also > several questions: > > 1. ide-cd uses the cdrom_info struct for e.g. dma status notification, the other > ide drivers use it per packet command in pc->flags. Well the last are kinda too > much to carry for _each_ command and i'm thinking maybe put all that in the > ide_drive_t and make it generic enough to fit all drivers. This way > pc->callback() can also be harboured there. One concern might be when a flag is > strictly per packet command which could be put somewhere else (maybe in the > struct request since it already has members when it is used as a packet > command).
Some pc->flags describe device's properties and thus should be moved to ide_drive_t (->dev_flags) while some other correspond to the queued command and moving them to ide_drive_t would be a bad idea IMO.
For ATA commands I was planning to put taskfile flags into rq->special field (well, I actually implemented it in draft patch and it looks OK) so maybe we can do something similar for packet commands.
> 2. Can all that pc->xferred, pc->b_count, pc->errors and pc->cur_pos accounting > be safely mapped to a rq? I see some discrepancies like is pc->buf_size == > rq->data_len, what about pc->req_xfer? I'll have a more detailed look at those > when i have more spare time later.
If you ask if they can be mapped 'directly' then the answer is: "probably no" but if the question is whether it is possible to do it after some changes then the answer is: "probably yes". :)
[ However it may be necessary to convert ATAPI drivers to use scatterlists instead of open-coded ->bio walking for PIO transfers first. ]
Thanks, Bart
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