On 2017-10-07 09:23 AM, Prabhakar Kushwaha wrote: > Dear Jagan, Simon, > > > -----Original Message----- > > From: U-Boot [mailto:u-boot-boun...@lists.denx.de] On Behalf Of Jagan > > Teki > > Sent: Thursday, December 07, 2017 11:19 AM > > To: Goldschmidt Simon <sgoldschm...@de.pepperl-fuchs.com> > > Cc: u-boot@lists.denx.de > > Subject: Re: [U-Boot] [PATCH] sf: ensure flash device is in 3-byte > > address mode > > > > On Tue, Dec 5, 2017 at 11:50 AM, Goldschmidt Simon > > <sgoldschm...@de.pepperl-fuchs.com> wrote: > > > + Lukasz (as a reviewer of my patch[1]) > > > > > > On Mon, Dec 4, 2017 at 8:20, Jagan Teki wrote: > > >> This is the patch[1] for 4-byte addressing, but I would wonder how > > >> can > > proceed > > >> operations with 4-byte if we disable during probe. > > >> > > >> [1] > > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgit. > > denx > > .de%2F%3Fp%3Du-boot- > > &data=02%7C01%7Cprabhakar.kushwaha%40nxp.com%7Ca37e67c0f5fd431396 > > 5f08d53d3649b8%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6364 > > > 82225771650679&sdata=CBQkKDXTE1g1mvEbYuyiBApW2NTxQFCirGeJV9uzX8E > > %3D&reserved=0 > > >> spi.git;a=commitdiff;h=fd0c22a90772379c4c11ba09347d36cc8ee17dca > > > > > > OK, so your patch does something different than what I did. > > > > > > I was trying to keep the change to U-Boot as small as possible, only > > > fixing this issue I was seeing: > > > > > > After a soft-reboot where the SPI chip was not reset, it is left in > > > 4-byte addressing mode (linux uses this mode, obviously). Remember > > > that 4-byte mode is not a permanent setting, so we can enter and > > > leave it any time we like by issuing a command. > > > > > > U-Boot uses the Bank Address Register (BAR) for spi flash chips with > > > more than 16 MByte, so it impclitly assumes that the chip is in > > > 3-byte address mode. As I see it, your patch is worth a discussion > > > named "should we use 4-byte addressing mode on spi flash chips?". > > > I do think this is a better alternative than writing BAR! But this > > > change probably needs discussion and testing. > > > > OK, will review your patch. > > > > Other solution to this problem could have been "adding support of 4byte > addressing". > > There will always be a requirement of supporting >16MB flash.
I would be very happy to have 4-byte addressing support. I just thought it would be better to first fix the soft-reboot issue I am having (and at least one other person on this list also had). Plus, I haven't seen a workign patch for 4-byte addressing on this list, yet. My patch has no side effects, works and could be merged for 2018.01. Thanks, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
