We Depends on linux-base because of linux-update-symlinks and
linux-check-removal. Those have been introduced in a version later than
4.0ubuntu1, which shipped on Xenial.
The unversioned Depends makes some upgrades to Bionic and installations of
linux-hwe-edge to break because those tools are not found during the configure
phase.
Signed-off-by: Thadeu Lima de Souza Cascardo <email address hidden>
Acked-by: Seth Forshee <email address hidden>
Acked-by: Andy Whitcroft <email address hidden>
Signed-off-by: Thadeu Lima de Souza Cascardo <email address hidden>
We assume that the CSB is written using the normal ringbuffer
coherency protocols, as outlined in kernel/events/ring_buffer.c:
* (HW) (DRIVER)
*
* if (LOAD ->data_tail) { LOAD ->data_head
* (A) smp_rmb() (C)
* STORE $data LOAD $data
* smp_wmb() (B) smp_mb() (D)
* STORE ->data_head STORE ->data_tail
* }
So we assume that the HW fulfils it's ordering requirements, and so we
should use a complimentary rmb() to ensure that our read of its WRITE
pointer is completed before we start accessing the data.
The final mb() is implied by the uncached mmio we perform to inform the
HW of our READ pointer.
References: https://bugs.freedesktop.org/show_bug.cgi?id=105064
References: https://bugs.freedesktop.org/show_bug.cgi?id=105888
References: https://bugs.freedesktop.org/show_bug.cgi?id=106185
References: 61bf9719fa17 ("drm/i915/cnl: Use mmio access to context status buffer")
Suggested-by: Mika Kuoppala <email address hidden>
Signed-off-by: Chris Wilson <email address hidden>
Cc: Mika Kuoppala <email address hidden>
Cc: Joonas Lahtinen <email address hidden>
Cc: Tvrtko Ursulin <email address hidden>
Cc: MichaĆ Winiarski <email address hidden>
Cc: Rafael Antognolli <email address hidden>
Cc: Michel Thierry <email address hidden>
Cc: Timo Aaltonen <email address hidden>
Signed-off-by: Timo Aaltonen <email address hidden>