Re: [PATCH v5 01/10] interconnect: qcom: rpm: make QoS INVALID default, separate out driver data

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 17/02/2023 10:46, Konrad Dybcio wrote:

I find this commit log difficult to understand.

Could you reduce it down ?

Currently, NOC_QOS_MODE_FIXED is defined as 0x0, which makes it the
"default" option (as that's what uninitialized members of partially
initialized structs are set to), which should really have been
NOC_QOS_MODE_INVALID, and that's what people (wrongly) assumed was
the case when .qos.qos_mode was not defined and what really makes
the most sense..

"Currently NOC_QOS_MODE_FIXED is defined as 0x0 which makes it the default option. The default option however should be NOC_QOS_MODE_INVALID"

That resulted in {port 0, prio 0, areq_prio 0, urg_fwd = false, rpm-voted}
QoS being always voted for, because the code flow assumed "hey, it's fixed
QoS, so let's just roll with whatever parameters are set" [again, set by
partial struct initialization, as these fields were left unfilled by the
developers]. That is of course incorrect, and on many of these platforms
port 0 is MAS_APPS_PROC, which 9/10 times is supposed to be handled by
the ap_owned path, not to mention the rest of the parameters may differ.
Arguably, the APPS node is the most important one, next to EBI0..

This paragraph in particular is difficult to decipher, at least for me with my native Dublinese


The modes are defined as preprocessor constants. They are not used
anywhere outside the driver or sent to any remote processor outside
qcom_icc_set_noc_qos(), which is easily worked around.
Separate the type specified in driver data from the value sent to msmbus.
Make the former an enum for better mainainability.

This is an implicit fix for every SMD RPM ICC driver that didn't
explicitly specify NOC_QOS_MODE_INVALID on non-AP_owned nodes that
don't have QoS settings.

It would be nice to reduce the commit log down to say three paragraphs of no more than three sentences each.

---
bod



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux