On 02.02.22 16:24, Kevin O'Connor wrote:
On Wed, Feb 02, 2022 at 11:50:50AM +0100, Alexander Graf wrote:
On 02.02.22 02:52, Kevin O'Connor wrote:
On Tue, Feb 01, 2022 at 08:39:10PM +0100, Florian Larysch wrote:
On Thu, Jan 27, 2022 at 11:37:52AM -0500, Kevin O'Connor wrote:
Thanks. I don't know enough about NVMe to review this patch though.
Maybe Julian or Alex could comment?
Happy to hear their comments on this. However, I can also try to explain
the reasoning in a bit more detail.
This follows from the NVMe spec[1]: The Identify command returns a data
structure that contains packed LBAF records (Figure 249, starting at
offset 131). This is represented by struct nvme_identify_ns in the
SeaBIOS code.
Figure 250 gives the structure of these records and this is where the
aforementioned discrepancy lies.
Thanks. I agree that this should be fixed in SeaBIOS.
However, your patch removes the "reserved" field, which doesn't look
correct. It sounds like the "res" struct member should remain, but
the "lbads" and "rp" members should be turned into a new "lbads_rp"
member. Also, the nvme.c code should be updated so that the read of
lbads performs the proper bit masking.
Looking at the spec, lbads is a full well aligned 8 bits. The collision here
is between rp and res, with rp taking only 2 bits and res the remaining 6.
Ah, I misread the spec. So, the original patch removing the "res"
struct member should be fine.
Yes, the original patch works too. There is currently no user of the rp
field, so nothing to mask against.
Is using bitfields acceptable in SeaBIOS? If so, the patch below should
automatically give us masking as well.
I'd recommend against using C bitfields to access hardware registers.
This is an in-RAM data structure. But in any case, let's just go with
the original patch.
Reviewed-by: Alexander Graf <g...@amazon.com>
Alex
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
_______________________________________________
SeaBIOS mailing list -- seabios@seabios.org
To unsubscribe send an email to seabios-le...@seabios.org
