[U-Boot] [PATCH] blk: Remove various places that do flush cache after read

[Qiang Zhao]

+Yangbo

Best Regards
Qiang Zhao

> -----Original Message-----
> From: York Sun
> Sent: Wednesday, August 23, 2017 12:49 AM
> To: Bin Meng <bmeng.cn at gmail.com>; Grygorii Strashko
> <grygorii.strashko at ti.com>; Michal Simek <michal.simek at xilinx.com>; Angelo
> Dureghello <angelo at sysam.it>; Kever Yang <kever.yang at rock-chips.com>;
> Jaehoon Chung <jh80.chung at samsung.com>; Albert Aribaud
> <albert.u.boot at aribaud.net>; Marcel Ziswiler <marcel.ziswiler at toradex.com>;
> Markus Niebel <Markus.Niebel at tq-group.com>; Z.q. Hou
> <zhiqiang.hou at nxp.com>; Sumit Garg <sumit.garg at nxp.com>; Joe Hershberger
> <joe.hershberger at ni.com>; Stefan Roese <sr at denx.de>; Wenbin Song
> <wenbin.song at nxp.com>; Qiang Zhao <qiang.zhao at nxp.com>; Simon Glass
> <sjg at chromium.org>; Max Krummenacher
> <max.krummenacher at toradex.com>; Masahiro Yamada
> <yamada.masahiro at socionext.com>; Tomas Melin
> <tomas.melin at vaisala.com>; Q.y. Gong <qianyu.gong at nxp.com>; Tom Rini
> <trini at konsulko.com>; U-Boot Mailing List <u-boot at lists.denx.de>
> Subject: Re: [PATCH] blk: Remove various places that do flush cache after read
> 
> On 08/21/2017 08:42 PM, Bin Meng wrote:
> > All these places seem to inherit the codes from the MMC driver where a
> > FIXME was put in the comment. However the correct operation after read
> > should be cache invalidate, not flush.
> >
> > The underlying drivers should be responsible for the cache operation.
> > Remove these codes completely.
> >
> > Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> > ---
> >
> >   arch/arm/cpu/armv8/fsl-layerscape/ppa.c | 15 ---------------
> >   board/toradex/common/tdx-cfg-block.c    |  2 --
> >   cmd/mmc.c                               |  2 --
> >   drivers/block/blk-uclass.c              |  3 ---
> >   drivers/block/blk_legacy.c              |  3 ---
> >   drivers/net/fm/fm.c                     |  2 --
> >   drivers/net/phy/cortina.c               |  2 --
> >   drivers/qe/qe.c                         |  2 --
> >   8 files changed, 31 deletions(-)
> >
> > diff --git a/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> > b/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> > index 24ddb5d..bbf8bba 100644
> > --- a/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> > +++ b/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> > @@ -107,9 +107,6 @@ int ppa_init(void)
> >   		return -EIO;
> >   	}
> >
> > -	/* flush cache after read */
> > -	flush_cache((ulong)fitp, cnt * 512);
> > -
> 
> NACK here.
> 
> 
> >   	ret = fdt_check_header(fitp);
> >   	if (ret) {
> >   		free(fitp);
> > @@ -134,9 +131,6 @@ int ppa_init(void)
> >   	}
> >   	debug("Read PPA header to 0x%p\n", ppa_hdr_ddr);
> >
> > -	/* flush cache after read */
> > -	flush_cache((ulong)ppa_hdr_ddr, cnt * 512);
> > -
> >   	ppa_esbc_hdr = (uintptr_t)ppa_hdr_ddr;
> >   #endif
> >
> > @@ -164,9 +158,6 @@ int ppa_init(void)
> >   		return -EIO;
> >   	}
> >
> > -	/* flush cache after read */
> > -	flush_cache((ulong)ppa_fit_addr, cnt * 512);
> > -
> >   #elif defined(CONFIG_SYS_LS_PPA_FW_IN_NAND)
> >   	struct fdt_header fit;
> >
> > @@ -208,9 +199,6 @@ int ppa_init(void)
> >   	}
> >   	debug("Read PPA header to 0x%p\n", ppa_hdr_ddr);
> >
> > -	/* flush cache after read */
> > -	flush_cache((ulong)ppa_hdr_ddr, fw_length);
> > -
> >   	ppa_esbc_hdr = (uintptr_t)ppa_hdr_ddr;
> >   #endif
> >
> > @@ -232,9 +220,6 @@ int ppa_init(void)
> >   		       CONFIG_SYS_LS_PPA_FW_ADDR);
> >   		return -EIO;
> >   	}
> > -
> > -	/* flush cache after read */
> > -	flush_cache((ulong)ppa_fit_addr, fw_length);
> >   #else
> >   #error "No CONFIG_SYS_LS_PPA_FW_IN_xxx defined"
> >   #endif
> 
> Hold on for ppa.c. We need to flush the cache after reading PPA image and it
> header after loading. These images need to be flushed into main memory. I will
> need to confirm with our team if we can remove flushing here.
> 
> York