On Thu, Jun 27, 2024 at 05:07:43PM +0200, Niklas Cassel wrote: > On Thu, Jun 27, 2024 at 01:54:34PM +0100, John Garry wrote: > > On 27/06/2024 13:32, Niklas Cassel wrote: > > > On Thu, Jun 27, 2024 at 01:26:04PM +0100, John Garry wrote: > > > > On 26/06/2024 19:00, Niklas Cassel wrote: > > > > > Hello all, > > > > > > > > > > This patch series was orginally meant to simply assign a unique id used > > > > > for printing earlier (ap->print_id), but has since grown to also include > > > > > cleanups related to ata_port_alloc() (since ap->print_id is now assigned > > > > > in ata_port_alloc()). > > > > > > > > > > > > > There's no real problem statement wrt print_id, telling how and why things > > > > are like they are, how it is a problem, and how it is improved in this > > > > series. > > > > > > You are right, it is missing from the cover-letter. > > > > > > It was there in v1: > > > https://lore.kernel.org/linux-ide/20240618153537.2687621-7-cassel@xxxxxxxxxx/ > > > > > > """ > > > This series moves the assignment of ap->print_id, which is used as a > > > unique id for each port, earlier, such that we can use the ata_port_* > > > print functions even before the ata_host has been registered. > > > """ > > > > OK, fine. > > > > I see code which checks vs ap->print_id, like: > > > > static void ata_force_link_limits(struct ata_link *link) > > { > > ... > > if (fe->port != -1 && fe->port != link->ap->print_id) > > continue; > > > > > > Is this all ok to deal with this print_id assignment change? > > > > To me, it seems natural to assign a valid print_id from the alloc time, so I > > can't help but wonder it was done the current way. > > ap->print_id was assigned after calling ata_host_register(), because libata > allowed a driver that did not know how many ports it had, to initially call > ata_alloc_host() with a big number of ports, and then reduce the host->n_ports > variable once it knew the actually number of ports, before calling > ata_host_register(), which would then free the "excess" ports. > > This feature has actually never been used by and driver, and I remove support > for this in this series: > https://lore.kernel.org/linux-ide/20240626180031.4050226-22-cassel@xxxxxxxxxx/ > > > However, you do raise a good point... > ap->print_id is just supposed to be used for printing, but it appears that > ata_force_link_limits() and some other ata_force_*() functions make use of > it for other things... sigh... > > Hopefully I can just change them from: > if (fe->port != -1 && fe->port != link->ap->print_id) > to > if (fe->port != -1) > > but I will need to look in to this further... So, looking more closely at this, the code is actually not abusing print_id. Looking at libata.force in Documentation/admin-guide/kernel-parameters.txt: [LIBATA] Force configurations. The format is a comma- separated list of "[ID:]VAL" where ID is PORT[.DEVICE]. PORT and DEVICE are decimal numbers matching port, link or device. Basically, it matches the ATA ID string printed on console by libata. While this seems a bit fragile, since it relies on the probe ordering of the SATA controller drivers, which could change, it does still work as designed after this series: I added the following to my kernel command line: "libata.force=5:nolpm" which yielded: [ 1.811464] ata3.00: FORCE: horkage modified (nolpm) [ 1.811466] ata3.00: LPM support broken, forcing max_power [ 1.811468] ata3.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100 [ 1.811470] ata3.00: 2097152 sectors, multi 16: LBA48 NCQ (depth 32) [ 1.811474] ata3.00: applying bridge limits [ 1.811535] ata3.00: LPM support broken, forcing max_power [ 1.811537] ata3.00: configured for UDMA/100 And considering that all checks against ap->print_id is for libata.force related parameters, I think that we are all good. Kind regards, Niklas
