On Nov 17 09:01, Cédric Le Goater wrote: > On 11/17/22 08:37, Klaus Jensen wrote: > > On Nov 17 07:56, Cédric Le Goater wrote: > > > On 11/17/22 07:40, Klaus Jensen wrote: > > > > On Nov 16 16:58, Cédric Le Goater wrote: > > > > > On 11/16/22 09:43, Klaus Jensen wrote: > > > > > > From: Klaus Jensen <k.jen...@samsung.com> > > > > > > > > > > > > It is not given that the current master will release the bus after a > > > > > > transfer ends. Only schedule a pending master if the bus is idle. > > > > > > > > > > > > Fixes: 37fa5ca42623 ("hw/i2c: support multiple masters") > > > > > > Signed-off-by: Klaus Jensen <k.jen...@samsung.com> > > > > > > --- > > > > > > hw/i2c/aspeed_i2c.c | 2 ++ > > > > > > hw/i2c/core.c | 37 ++++++++++++++++++++++--------------- > > > > > > include/hw/i2c/i2c.h | 2 ++ > > > > > > 3 files changed, 26 insertions(+), 15 deletions(-) > > > > > > > > > > > > diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c > > > > > > index c166fd20fa11..1f071a3811f7 100644 > > > > > > --- a/hw/i2c/aspeed_i2c.c > > > > > > +++ b/hw/i2c/aspeed_i2c.c > > > > > > @@ -550,6 +550,8 @@ static void > > > > > > aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) > > > > > > } > > > > > > SHARED_ARRAY_FIELD_DP32(bus->regs, reg_cmd, M_STOP_CMD, > > > > > > 0); > > > > > > aspeed_i2c_set_state(bus, I2CD_IDLE); > > > > > > + > > > > > > + i2c_schedule_pending_master(bus->bus); > > > > > > > > > > Shouldn't it be i2c_bus_release() ? > > > > > > > > > > > > > The reason for having both i2c_bus_release() and > > > > i2c_schedule_pending_master() is that i2c_bus_release() sort of pairs > > > > with i2c_bus_master(). They either set or clear the bus->bh member. > > > > > > > > In the current design, the controller (in this case the Aspeed I2C) is > > > > an "implicit" master (it does not have a bottom half driving it), so > > > > there is no bus->bh to clear. > > > > > > > > I should (and will) write some documentation on the asynchronous API. > > > > > > I found the routine names confusing. Thanks for the clarification. > > > > > > Maybe we could do this rename : > > > > > > i2c_bus_release() -> i2c_bus_release_and_clear() > > > i2c_schedule_pending_master() -> i2c_bus_release() > > > > > > and keep i2c_schedule_pending_master() internal the I2C core subsystem. > > > > > > > How about renaming i2c_bus_master to i2c_bus_acquire() such that it > > pairs with i2c_bus_release(). > > Looks good to me. > > > And then add an i2c_bus_yield() to be used by the controller? I think we > > should be able to assert in i2c_bus_yield() that bus->bh is NULL. But > > I'll take a closer look at that. > > I am using your i2c-echo slave device to track regressions in the Aspeed > machines. May be we could merge it for tests ? >
Oh, cool. Sure, I'd be happy to help "maintain" it ;)
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