From: Manivannan Sadhasivam <mani@kernel.org>
To: Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc: Qiang Yu <quic_qianyu@quicinc.com>,
mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, quic_cang@quicinc.com,
quic_mrana@quicinc.com, Bhaumik Bhatt <quic_bbhatt@quicinc.com>
Subject: Re: [PATCH] bus: mhi: host: Add sysfs entry to force device to enter EDL
Date: Tue, 2 Jan 2024 22:22:29 +0530 [thread overview]
Message-ID: <20240102165229.GC4917@thinkpad> (raw)
In-Reply-To: <cff4b828-9566-a2bd-287a-138d74a76a59@quicinc.com>
On Tue, Jan 02, 2024 at 08:31:15AM -0700, Jeffrey Hugo wrote:
> On 12/25/2023 12:47 AM, Qiang Yu wrote:
> > From: Bhaumik Bhatt <quic_bbhatt@quicinc.com>
> >
> > Forcing the device (eg. SDX75) to enter Emergency Download Mode involves
> > writing the 0xEDEDEDED cookie to the channel 91 doorbell register and
> > forcing an SOC reset afterwards. Allow users of the MHI bus to exercise the
> > sequence using a sysfs entry.
>
> I don't see this documented in the spec anywhere. Is this standard behavior
> for all MHI devices?
>
> What about devices that don't support EDL mode?
>
> How should the host avoid using this special cookie when EDL mode is not
> desired?
>
All points raised by Jeff are valid. I had discussions with Hemant and Bhaumik
previously on allowing the devices to enter EDL mode in a generic manner and we
didn't conclude on one final approach.
Whatever way we come up with, it should be properly described in the MHI spec
and _should_ be backwards compatible.
- Mani
> -Jeff
--
மணிவண்ணன் சதாசிவம்
next prev parent reply other threads:[~2024-01-02 16:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-25 7:47 [PATCH] bus: mhi: host: Add sysfs entry to force device to enter EDL Qiang Yu
2024-01-02 15:31 ` Jeffrey Hugo
2024-01-02 16:52 ` Manivannan Sadhasivam [this message]
2024-01-09 9:20 ` Qiang Yu
2024-01-11 19:08 ` Jeffrey Hugo
2024-04-02 4:34 ` Qiang Yu
2024-04-02 13:52 ` Qiang Yu
2024-04-02 15:33 ` Jeffrey Hugo
2024-04-03 5:44 ` Qiang Yu
2024-04-08 8:10 ` Qiang Yu
2024-04-08 10:15 ` Manivannan Sadhasivam
2024-04-09 3:32 ` Qiang Yu
2024-01-09 8:43 ` Qiang Yu
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