3 ms·

What a way to shoot a great product in the foot. How does a "mandate" like that work? What if someone uses a different PMIC? Or, what if they include one "mand

by nomel 3y ago

What a way to shoot a great product in the foot. How does a "mandate" like that work? What if someone uses a different PMIC? Or, what if they include one "mandated" PMIC for boot, then offload to a sane one a few hundred ms later?

duskwuff 3y ago
> How does a "mandate" like that work? A couple of different levels of mandate come to mind, some of which may overlap: 1. Qualcomm won't sell you the SoC without the appropriate number of their PMICs to support it. 2. Qualcomm's reference designs only include their PMICs, and the datasheets don't tell you what electrical requirements those parts are satisfying. 3. The reference firmware from Qualcomm expects those PMICs to be present, and will panic if they aren't. 4. Same as #3, except it's in the boot ROM. 5. Part of the power supply is internal to the SoC, and the matching Qualcomm PMIC is required to complete it. The SemiAccurate article suggests that #1 and #2 are definitely the case, and #3-5 may be true as well.
- uxp100 3y ago
  Supporting a wide variety of pmics in bootrom is quite a bit of work, and can be an attack surface. Hardcoding pmic details in bootrom sounds nice. If I worked on Qualcomm boot and they did 1-3 but still made BR have pmic flexibility I would br annoyed. Though if you work on boot you’re always a little annoyed.
canucker2016 3y ago
the article mentions the OEM reactions. could the OEMs pay for the QCOM PMIC but use a different PMIC in their laptop? QCOM says no because there are proprietary protocols between the SOC (the CPU part) and the PMIC. The QCOM PMIC, multiple of them in order to handle the workload on a laptop, would require a more expensive PCB as well. The proprietary SOC-PMIC protocol would preclude the use of a non-QCOM PMIC. The article states that QCOM is giving the OEMs money to placate them, more than the actual revenue from the PMICs. But that won't help the power usage of the system. So look carefully at the power usage benchmarks for the new QCOM-powered laptops.
- throwaway72839 3y ago
  I’ve been part of unrelated projects that involved SoC part selection and negotiation with… large chip vendors. They always pull this shit, although this case seems particularly annoying. They’ll tie their SoC to some other random part, invent some proprietary protocol to brand it with, and then get upset when you say you don’t want the extras. I’m sure there are some technical advantages to their solutions, but they’re just as often bloated and not appropriate for the design. We all know that chip vendors don’t exactly write the best code, that’s expected. But inviting even more proprietary drivers or even blobs(!), for a solution that sales says will just work and solve all our problems, is usually a risky move. Heavily modifying or reimplementing boot code and drivers is an inevitability, and no engineer who’s been through that is going to invite more blobs into their codebase if they can avoid it.
- pinewurst 3y ago
  https://www.tomshardware.com/news/qualcomm-snapdragon-elite-x-oryon-pc-cpu-specs https://www.tomshardware.com/news/qualcomm-snapdragon-elite-... “Over the summer, reports popped up that Qualcomm was requiring the use of its power management integrated circuits (PMICs) with the Oryon-based processors. Kondap said that Qualcomm's PMICs are "an option for OEMs to choose," and that the company has been providing them for "many years now."”

by nomel 3y ago

duskwuff 3y ago

> How does a "mandate" like that work? A couple of different levels of mandate come to mind, some of which may overlap: 1. Qualcomm won't sell you the SoC without the appropriate number of their PMICs to support it. 2. Qualcomm's reference designs only include their PMICs, and the datasheets don't tell you what electrical requirements those parts are satisfying. 3. The reference firmware from Qualcomm expects those PMICs to be present, and will panic if they aren't. 4. Same as #3, except it's in the boot ROM. 5. Part of the power supply is internal to the SoC, and the matching Qualcomm PMIC is required to complete it. The SemiAccurate article suggests that #1 and #2 are definitely the case, and #3-5 may be true as well.

uxp100 3y ago
Supporting a wide variety of pmics in bootrom is quite a bit of work, and can be an attack surface. Hardcoding pmic details in bootrom sounds nice. If I worked on Qualcomm boot and they did 1-3 but still made BR have pmic flexibility I would br annoyed. Though if you work on boot you’re always a little annoyed.

canucker2016 3y ago

the article mentions the OEM reactions. could the OEMs pay for the QCOM PMIC but use a different PMIC in their laptop? QCOM says no because there are proprietary protocols between the SOC (the CPU part) and the PMIC. The QCOM PMIC, multiple of them in order to handle the workload on a laptop, would require a more expensive PCB as well. The proprietary SOC-PMIC protocol would preclude the use of a non-QCOM PMIC. The article states that QCOM is giving the OEMs money to placate them, more than the actual revenue from the PMICs. But that won't help the power usage of the system. So look carefully at the power usage benchmarks for the new QCOM-powered laptops.

throwaway72839 3y ago
I’ve been part of unrelated projects that involved SoC part selection and negotiation with… large chip vendors. They always pull this shit, although this case seems particularly annoying. They’ll tie their SoC to some other random part, invent some proprietary protocol to brand it with, and then get upset when you say you don’t want the extras. I’m sure there are some technical advantages to their solutions, but they’re just as often bloated and not appropriate for the design. We all know that chip vendors don’t exactly write the best code, that’s expected. But inviting even more proprietary drivers or even blobs(!), for a solution that sales says will just work and solve all our problems, is usually a risky move. Heavily modifying or reimplementing boot code and drivers is an inevitability, and no engineer who’s been through that is going to invite more blobs into their codebase if they can avoid it.
pinewurst 3y ago
https://www.tomshardware.com/news/qualcomm-snapdragon-elite-x-oryon-pc-cpu-specs https://www.tomshardware.com/news/qualcomm-snapdragon-elite-... “Over the summer, reports popped up that Qualcomm was requiring the use of its power management integrated circuits (PMICs) with the Oryon-based processors. Kondap said that Qualcomm's PMICs are "an option for OEMs to choose," and that the company has been providing them for "many years now."”