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From: R, Sricharan <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: Fri, 15 Jun 2012 20:18:23 +0530	[thread overview]
Message-ID: <CAJ7qFSf_o_e99t2NjHNaHs8-Gzp7szu5K=GahpfmWjQxwp-Ydw@mail.gmail.com> (raw)
In-Reply-To: <4FDB41BE.40204@ti.com>

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.

 So we invalidate it before jumping to kernel.

In fact our procedure of turning off the caches and MMU should
have a relook, to really ensure things are safe. I will check on
this more.

>> ? ?If it is a problem with unaligned regions, then that is the only
>> thing to be fixed
>> ? right ?. Just trying to understand why this change is required ?
>
> The problem is that within the USB/network/filesystem stacks we have a
> lot of not cache safe alignments apparently. ?Without this every '#' of
> a tftp gives a screen full of error printfs. ?So tftp'ing a kernel takes
> minutes, not seconds, to complete.
>
 Ok,but when buffers are not aligned
   isn't that you are going to have coherency problems ?

Thanks,
 Sricharan

  parent reply	other threads:[~2012-06-15 14:48 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 [this message]
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
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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