On Sun, 25 Apr 2021, John Paul Adrian Glaubitz wrote:
On 4/25/21 11:06 AM, Finn Thain wrote:
This was tested on my Quadra 630. I haven't tested it on my PowerBook 150
because I don't have a RAM adapter board for it.
Apparently, the hardware I tested doesn't need macide_clear_irq() or
macide_test_irq() -- if it did, the generic driver would not have worked.
It's possible that those routines are needed for the PowerBook 150 but
we can cross that bridge if and when we come to it.
BTW, macide_clear_irq() appears to suffer from a race condition. The write
to the interrupt flags register could easily have unintended side effects
as it may alter other flag bits. Fortunately, all of the other bits are
unused by Linux. Moreover, when tested on my Quadra 630, that assignment
(*ide_ifr &= ~0x20) was observed to have no effect on bit 5.
Shouldn't we switch to a libata driver instead with legacy IDE been slated
for removal from the Linux kernel?
This patch means that the Quadra 630/580 config will work the same as the
Powerbook 190 config. Please see commit 50c5feeea0af ("ide/macide: Convert
Mac IDE driver to platform driver") for some background.
This patch also means that the kernel/drivers/ide/macide.ko driver module
will disappear completely. The module that will replace it is up to you.
If you enable CONFIG_IDE and CONFIG_BLK_DEV_PLATFORM, Quadras and
Powerbooks will use the kernel/drivers/ide/ide_platform.ko module.
If you enable CONFIG_ATA and CONFIG_PATA_PLATFORM, Quadras and
Powerbooks will use the kernel/drivers/ata/pata_platform.ko module.
(If you enable all of the above, you may need to use a blacklist to ensure
that the preferred driver module gets loaded.)
Was macide the only IDE driver in Debian/m68k kernels without a libata
alternative? If so, this patch would allow you to finally drop CONFIG_IDE.
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@xxxxxxxxxx
`. `' Freie Universitaet Berlin - glaubitz@xxxxxxxxxxxxxxxxxxx
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