Re: [PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0]

2020-10-20 Thread Joel Stanley
On Tue, 20 Oct 2020 at 06:23, Benjamin Herrenschmidt wrote: > > On Tue, 2020-10-20 at 04:13 +, Joel Stanley wrote: > > On Mon, 19 Oct 2020 at 23:20, Benjamin Herrenschmidt > > wrote: > > > > > > On Mon, 2020-10-19 at 16:57 +0800, Dylan Hung wrote: > > > > These rules must be followed when acc

Re: [PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0]

2020-10-19 Thread Benjamin Herrenschmidt
On Tue, 2020-10-20 at 04:13 +, Joel Stanley wrote: > On Mon, 19 Oct 2020 at 23:20, Benjamin Herrenschmidt > wrote: > > > > On Mon, 2020-10-19 at 16:57 +0800, Dylan Hung wrote: > > > These rules must be followed when accessing the TX descriptor: > > > > > > 1. A TX descriptor is "cleanable" o

Re: [PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0]

2020-10-19 Thread Joel Stanley
On Mon, 19 Oct 2020 at 23:20, Benjamin Herrenschmidt wrote: > > On Mon, 2020-10-19 at 16:57 +0800, Dylan Hung wrote: > > These rules must be followed when accessing the TX descriptor: > > > > 1. A TX descriptor is "cleanable" only when its value is non-zero > > and the owner bit is set to "softwar

Re: [PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0]

2020-10-19 Thread Benjamin Herrenschmidt
On Mon, 2020-10-19 at 16:57 +0800, Dylan Hung wrote: > These rules must be followed when accessing the TX descriptor: > > 1. A TX descriptor is "cleanable" only when its value is non-zero > and the owner bit is set to "software" Can you elaborate ? What is the point of that change ? The owner bit

[PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0]

2020-10-19 Thread Dylan Hung
These rules must be followed when accessing the TX descriptor: 1. A TX descriptor is "cleanable" only when its value is non-zero and the owner bit is set to "software" 2. A TX descriptor is "writable" only when its value is zero regardless the edotr mask. Fixes: 52c0cae87465 ("ftgmac100: Remove