From: Tom Rini <trini@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: Mon, 18 Jun 2012 08:23:27 -0700 [thread overview]
Message-ID: <4FDF47EF.2030103@ti.com> (raw)
In-Reply-To: <CAJ7qFSdWKKcyBvj+DRag3w3B_XUJoTK5uaMu-bsryZUij6PUww@mail.gmail.com>
On 06/18/2012 07:13 AM, R, Sricharan wrote:
> Hi Tom,
>
> On Fri, Jun 15, 2012 at 8:50 PM, Tom Rini <trini@ti.com> wrote:
>> On 06/15/2012 08:18 AM, R, Sricharan wrote:
>>> Hi,
>>> [snip..]
>>>>>>> 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 ?
>>>>
>>>> Exactly. USB requires dcache to be turned off today. With it turned
>>>> off it spams these messages making tftp to an aligned address take
>>>> minutes because the console is busy printing all of these messages about
>>>> flushes it didn't need to do. The alternative is to build
>>>> omap4/omap5/etc with dcache disabled or USB disabled.
>>>>
>>> Ok, but who is calling cache maintenance in your case after
>>> turning off caches ?
>>
>> The USB stack currently.
>
> Ok, in that case if
> 1) Alignment issue has to be fixed USB stack, (or)
This is the correct, long term solution.
> 2) Better to turn off caches when say USB-EHCI is enabled ?
Doing that is what showed the issue to start with. Running 'dcache off'
doesn't turn off attempted cache flushing.
> (or)
>
> 3) Turn of caches until cache library is fixed so that
> we will not require any maintenance after turning it off.
> ( I will work on this some time, this week)
This is also a good thing. It just needs to make sure attempted flushes
don't spam the console, when cache is off :)
> I am not sure which one to do, but definitely we should not
> prevent it from executing as in the above patch. This may
> lead to other issues.
OK. I'll see how badly boot time goes up when dcache is off to start
with on a few boards.
--
Tom
next prev parent reply other threads:[~2012-06-18 15:23 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 [this message]
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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