Thread (7 messages) 7 messages, 3 authors, 2025-08-04

Re: [PATCH] mmc: sdhci-of-arasan: Ensure CD logic stabilization before power-up

From: Prasanna Kumar T S M <hidden>
Date: 2025-08-01 13:03:49
Also in: linux-mmc, lkml

Hi Sai Krishna,

On 25-07-2025 11:19, Potthuri, Sai Krishna wrote:
quoted
Will this work with all Arasan variants?
Yes, this is expected to work across all Arasan variants that comply with the standard
SDHCI register definitions. The SDHCI_CD_STABLE bit is defined in both the
standard SDHCI specification and Arasan's user guide.
As SDHCI_CD_STABLE bit is defined in SDHCI specification, why are you 
making a driver specific fix? Is this problem specific to Arasan eMMC? 
If not, does it make sense to make this a framework level change instead 
of a driver specific change?

Given that you are planning to add a quirk, doing this in common code 
would be better.
On Xilinx/AMD Versal and ZynqMP platforms, the CD stable bit is typically set within
a few milliseconds. However, to be on the safer side and ensure compatibility across
all Arasan variants, a timeout of 1 second is added.
Please let me know if you prefer to increase the timeout or if this logic should be
enabled by a platform specific quirk.
Thanks,

Prasanna Kumar

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