On Sun, Dec 31, 2023 at 11:27 PM Bhumkar, Tejas Arvind <tejas.arvind.bhum...@amd.com> wrote: > > [AMD Official Use Only - General] > > Hi Jagan, > > > -----Original Message----- > > From: Jagan Teki <ja...@amarulasolutions.com> > > Sent: Wednesday, December 20, 2023 1:00 PM > > To: Bhumkar, Tejas Arvind <tejas.arvind.bhum...@amd.com> > > Cc: u-boot@lists.denx.de; joe.hershber...@ni.com; rfried....@gmail.com; > > Simek, Michal <michal.si...@amd.com>; vigne...@ti.com; g...@xilinx.com; T > > Karthik Reddy <t.karthik.re...@amd.com> > > Subject: Re: [PATCH v2 01/30] mtd: spi-nor: Add config to enable flash DTR > > > > Caution: This message originated from an External Source. Use proper caution > > when opening attachments, clicking links, or responding. > > > > > > On Wed, Dec 6, 2023 at 3:02 PM Tejas Bhumkar > > <tejas.arvind.bhum...@amd.com> wrote: > > > > > > From: T Karthik Reddy <t.karthik.re...@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.
