On Sun, Dec 31, 2023 at 11:27 PM Bhumkar, Tejas Arvind tejas.arvind.bhumkar@amd.com wrote:
[AMD Official Use Only - General]
Hi Jagan,
-----Original Message----- From: Jagan Teki jagan@amarulasolutions.com Sent: Wednesday, December 20, 2023 1:00 PM To: Bhumkar, Tejas Arvind tejas.arvind.bhumkar@amd.com Cc: u-boot@lists.denx.de; joe.hershberger@ni.com; rfried.dev@gmail.com; Simek, Michal michal.simek@amd.com; vigneshr@ti.com; git@xilinx.com; T Karthik Reddy t.karthik.reddy@amd.com Subject: Re: [PATCH v2 01/30] mtd: spi-nor: Add config to enable flash DTR
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On Wed, Dec 6, 2023 at 3:02 PM Tejas Bhumkar tejas.arvind.bhumkar@amd.com wrote:
From: T Karthik Reddy t.karthik.reddy@amd.com
The spi-nor framework will set up the flash parameters by reading the flash id table flags, which include cmd opcodes, address width, dummy bytes, and bus width. In case, flash supports octal DTR mode and the controller does not support the DTR. There is no process to switch back to SDR mode. To avoid this issue, create a Kconfig option SPI_FLASH_DTR_ENABLE to explicitly specify to enable/disable flash DTR support. This config is disabled by default.
We cannot control controller fixup in flash, DTR read based on the DTR flag I don't think adding extra CONFIG to hack the controller with impact is.
[Tejas] : By default, this configuration is set to Disabled. It serves as a convenient option for operating the flash between SDR and DDR without requiring any adjustments to the nor-id table flags.
This look like controller hack to me, may be a clear negotiation b/w controller and flag might have proper solution.
Jagan.