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From: Sricharan R <r.sricharan@ti.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/4] cache_v7: Check for dcache enablement in dcache flush functions
Date: Thu, 21 Jun 2012 14:55:18 +0530	[thread overview]
Message-ID: <964b66f1cf8dc34b5ecdadf684fd6c02@mail.gmail.com> (raw)
In-Reply-To: <4FE1FE69.5080807@ti.com>

Hi,
[snip..]
> On 06/15/2012 07:48 AM, R, Sricharan wrote:
> > Hi,
> >
> >>> On Fri, Jun 15, 2012 at 12:31 AM, Tom Rini<trini@ti.com>  wrote:
> >>>> If we are built with D-CACHE enabled but have run 'dcache off' and
> then
> >>>> attempt to flush unaligned regions we spam the console with
> problems
> >>>> that aren't true (as the cache was off).
> >>>>
> >>>    Today we do cache maintenance operations after the dcache is
> turned off.
> >>>    One example is before jumping to kernel, we try to invalidate
> the caches,
> >>>    in cache turned off state. So with this patch those maintenance
> calls will
> >>>    do nothing, which is not correct.
> >>
> >> Ah yes,  But, shouldn't we be doing these same operations as part of
> >> turning the cache off?
> >>
> >    The problem is that while turning of dcaches, we flush it, and
> turn
> >   cache and MMU off.  But these operations are not happening
> >   automatically in a single call. So there is a chance of  valid
> >   entries present in cache even after it is OFF.
>
> I think this is what we need to fix. Otherwise, Tom's change looks good
> to me. How about an invalidate in dcache_disable() or something like
> that?
>
  Correct. So if the cleaning up sequence is fine, then ok.
  So there should be no need to check if caches are OFF inside
  the maintenance functions. Kernel does not looks like doing such checks.
  The real issue looks like we should have had assembly level functions
  to do the cleanup routines for flush-invalidate-turn OFF caches/MMU
atomically.

Thanks,
 Sricharan

  reply	other threads:[~2012-06-21  9:25 UTC|newest]

Thread overview: 85+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-14 19:01 [U-Boot] [PATCH 0/4] USB and cache related fixes Tom Rini
2012-06-14 19:01 ` [U-Boot] [PATCH 1/4] ehci-omap: Do not call dcache_off from omap_ehci_hcd_init Tom Rini
2012-06-14 21:57   ` Marek Vasut
2012-06-14 22:14     ` Tom Rini
2012-06-14 19:01 ` [U-Boot] [PATCH 2/4] cache_v7: Check for dcache enablement in dcache flush functions Tom Rini
2012-06-14 22:00   ` Marek Vasut
2012-06-14 22:11     ` Tom Rini
2012-06-14 23:17       ` Marek Vasut
2012-06-15  5:48   ` R, Sricharan
2012-06-15 14:07     ` Tom Rini
2012-06-15 14:25       ` Marek Vasut
2012-06-15 14:30         ` Tom Rini
2012-06-15 14:33           ` Marek Vasut
2012-06-15 14:48       ` R, Sricharan
2012-06-15 15:00         ` Tom Rini
2012-06-15 15:18           ` R, Sricharan
2012-06-15 15:20             ` Tom Rini
2012-06-18 14:13               ` R, Sricharan
2012-06-18 15:23                 ` Tom Rini
2012-06-20 16:46         ` Aneesh V
2012-06-21  9:25           ` Sricharan R [this message]
2012-06-21 15:23             ` R, Sricharan
2012-06-27 23:40               ` Aneesh V
2012-06-28  5:49                 ` R, Sricharan
2012-06-27 23:17             ` Aneesh V
2012-06-14 19:01 ` [U-Boot] [PATCH 3/4] ehci-hcd.c: Add a new USB_DMA_MINALIGN define for cache alignment Tom Rini
2012-06-14 19:29   ` Marek Vasut
2012-06-14 19:30     ` Tom Rini
2012-06-14 19:41       ` Marek Vasut
2012-06-14 19:54         ` Tom Rini
2012-06-14 20:02           ` Marek Vasut
2012-06-14 19:01 ` [U-Boot] [PATCH 4/4] musb_core.h: " Tom Rini
2012-06-14 21:45 ` [U-Boot] [PATCH v2 0/3] USB and cache related fixes Tom Rini
2012-06-14 21:45   ` [U-Boot] [PATCH v2 1/3] ehci-omap: Do not call dcache_off from omap_ehci_hcd_init Tom Rini
2012-06-14 21:45   ` [U-Boot] [PATCH v2 2/3] cache_v7: Check for dcache enablement in dcache flush functions Tom Rini
2012-06-14 21:45   ` [U-Boot] [PATCH v2 3/3] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment Tom Rini
2012-06-20 16:21   ` [U-Boot] [PATCH v3 0/6] USB and cache related fixes Tom Rini
2012-06-20 16:21     ` [U-Boot] [PATCH v3 1/6] ehci-omap: Do not call dcache_off from omap_ehci_hcd_init Tom Rini
2012-06-20 16:21     ` [U-Boot] [PATCH v3 2/6] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment Tom Rini
2012-06-20 19:00       ` Marek Vasut
2012-06-20 19:15         ` Tom Rini
2012-06-20 21:15           ` Marek Vasut
2012-06-20 22:07             ` Tom Rini
2012-06-21  0:09               ` Marek Vasut
2012-06-20 16:21     ` [U-Boot] [PATCH v3 3/6] mcx: Disable DCACHE since USB EHCI is enabled Tom Rini
2012-06-20 16:21     ` [U-Boot] [PATCH v3 4/6] omap3_beagle: " Tom Rini
2012-06-20 16:21     ` [U-Boot] [PATCH v3 5/6] omap4_panda: " Tom Rini
2012-06-20 16:21     ` [U-Boot] [PATCH v3 6/6] tam3517-common: " Tom Rini
2012-06-20 22:14     ` [U-Boot] [PATCH v4 0/6] USB and cache related fixes Tom Rini
2012-06-20 22:14       ` [U-Boot] [PATCH v4 1/6] ehci-omap: Do not call dcache_off from omap_ehci_hcd_init Tom Rini
2012-06-20 22:14       ` [U-Boot] [PATCH v4 2/6] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment Tom Rini
2012-06-20 22:14       ` [U-Boot] [PATCH v4 3/6] mcx: Disable DCACHE since USB EHCI is enabled Tom Rini
2012-06-27 22:28         ` Ilya Yanok
2012-06-27 22:48           ` Marek Vasut
2012-06-28 13:57             ` Ilya Yanok
2012-06-28 14:37               ` Marek Vasut
2012-06-28 14:57                 ` Ilya Yanok
2012-06-28 15:41                   ` Marek Vasut
2012-06-30 15:51                     ` Ilya Yanok
2012-06-30 19:27                       ` Marek Vasut
2012-07-03 20:10                         ` Ilya Yanok
2012-07-03 21:23                           ` Marek Vasut
2012-06-28 17:29                 ` Tom Rini
2012-06-28 22:01                   ` Marek Vasut
2012-06-28 22:34                     ` Tom Rini
2012-06-28 22:36                       ` Marek Vasut
2012-06-28 23:01                         ` Tom Rini
2012-06-29  0:54                           ` Marek Vasut
2012-06-29  2:14                             ` Tom Rini
2012-06-30 15:55                             ` Ilya Yanok
2012-06-30 19:28                               ` Marek Vasut
2012-07-03 20:13                                 ` Ilya Yanok
2012-07-03 20:43                                   ` Tom Rini
2012-07-03 21:12                                     ` Ilya Yanok
2012-07-04  0:14                                       ` Marek Vasut
2012-07-04 13:08                                         ` Ilya Yanok
2012-07-03 21:24                                     ` Marek Vasut
2012-06-20 22:14       ` [U-Boot] [PATCH v4 4/6] omap3_beagle: " Tom Rini
2012-06-20 22:14       ` [U-Boot] [PATCH v4 5/6] omap4_panda: " Tom Rini
2012-06-21 11:19         ` Sricharan R
2012-06-21 16:40           ` R, Sricharan
2012-06-20 22:14       ` [U-Boot] [PATCH v4 6/6] tam3517-common: " Tom Rini
2012-06-14 22:02 ` [U-Boot] [PATCH 0/4] USB and cache related fixes Marek Vasut
2012-06-14 22:13   ` Tom Rini
2012-06-14 23:17     ` Marek Vasut

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