Messages in this thread | | | Date | Sun, 7 Apr 2024 19:37:12 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 6.8 39/68] net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses |
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On Tue, Apr 02, 2024 at 05:41:44AM -0700, Florian Fainelli wrote: > > >On 3/29/2024 5:25 AM, Sasha Levin wrote: >>From: Florian Fainelli <florian.fainelli@broadcom.com> >> >>[ Upstream commit ee975351cf0c2a11cdf97eae58265c126cb32850 ] >> >>Up until now we have managed not to have the mdio-bcm-unimac manage its >>clock except during probe and suspend/resume. This works most of the >>time, except where it does not. >> >>With a fully modular build, we can get into a situation whereby the >>GENET driver is fully registered, and so is the mdio-bcm-unimac driver, >>however the Ethernet PHY driver is not yet, because it depends on a >>resource that is not yet available (e.g.: GPIO provider). In that state, >>the network device is not usable yet, and so to conserve power, the >>GENET driver will have turned off its "main" clock which feeds its MDIO >>controller. >> >>When the PHY driver finally probes however, we make an access to the PHY >>registers to e.g.: disable interrupts, and this causes a bus error >>within the MDIO controller space because the MDIO controller clock(s) >>are turned off. >> >>To remedy that, we manage the clock around all of the I/O accesses to >>the hardware which are done exclusively during read, write and clock >>divider configuration. >> >>This ensures that the register space is accessible, and this also >>ensures that there are not unnecessarily elevated reference counts >>keeping the clocks active when the network device is administratively >>turned off. It would be the case with the previous way of managing the >>clock. >> >>Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> >>Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> >>Signed-off-by: David S. Miller <davem@davemloft.net> >>Signed-off-by: Sasha Levin <sashal@kernel.org> > >Please drop this patch, it is usable in isolation and needs 2 >additional patches to be meaningful: > >https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee2b4cf8b281606bbf332cbd73ce2a73eac417f0 >https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >/commit/?id=ba0b78371c46b2104197ff2c244f13f011ddfa80
Ack, thanks!
-- Thanks, Sasha
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