From: Lukasz Majewski <l.majewski@samsung.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/6] usb:udc:samsung: Remove redundant cache operation from Samsung UDC driver
Date: Tue, 04 Feb 2014 07:23:38 +0100 [thread overview]
Message-ID: <20140204072338.08b518db@amdc2363> (raw)
In-Reply-To: <201402031906.59954.marex@denx.de>
Hi Marek,
> On Monday, February 03, 2014 at 09:05:06 AM, Lukasz Majewski wrote:
>
> [...]
>
> > > > To sum up:
> > > >
> > > > 1. s3c_udc_ep0_zlp - EP0 ZLP packets don't need to invalidate
> > > > the cache (since it is zero length transmission)
> > > >
> > > > 2. s3c_udc_pre_setup - cache invalidation is not needed when I
> > > > setup buffer for OUT EP0 transmission.
> > > >
> > > > The above two invalidation calls had been added by me, and are
> > > > mine mistakes. Those don't contribute to transmission speed up
> > > > (and shall be regarded as a cosmetic changes)
> > > >
> > > > 3. setdma_rx - here I invalidate parts of the s3c UDC driver's
> > > > internal buffer. This call is not needed anymore since we reuse
> > > > the buffers passed from gadgets.
> > >
> > > And you do correct cache management on those in the UDC driver or
> > > in the gadget driver ?
> >
> > For download, buffers are allocated in gadgets. Then buffer is
> > passed to the UDC driver in a USB request.
> > After receiving data via USB the UDC driver takes care to invalidate
> > cache, hence the gadget can work on the data.
> >
> > Cache management is performed in the UDC driver.
>
> OK, this is the correct place. I just wanted to make sure about this.
> Thanks :)
No problem :-)
>
> > > > This is the key speed improvement here.
> > >
> > > This should be in the commit message really ;-)
> >
> > I wrongly assumed, that code explains what was the rationale :-).
> > I'm going to prepare more verbose commit message for v2.
>
> Please do, thanks!
>
> Best regards,
> Marek Vasut
--
Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
next prev parent reply other threads:[~2014-02-04 6:23 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-31 12:16 [U-Boot] [PATCH 0/6] usb:samsung: Exynos4 SoC USB code improvements Lukasz Majewski
2014-01-31 12:16 ` [U-Boot] [PATCH 1/6] usb:gadget:ums: Replace malloc calls with memalign to fix cache buffer alignment Lukasz Majewski
2014-02-01 2:48 ` Marek Vasut
2014-02-01 9:10 ` Lukasz Majewski
2014-01-31 12:16 ` [U-Boot] [PATCH 2/6] usb:udc:samsung: Remove redundant cache operation from Samsung UDC driver Lukasz Majewski
2014-02-01 2:50 ` Marek Vasut
2014-02-01 9:56 ` Lukasz Majewski
2014-02-01 22:49 ` Marek Vasut
2014-02-03 8:05 ` Lukasz Majewski
2014-02-03 18:06 ` Marek Vasut
2014-02-04 6:23 ` Lukasz Majewski [this message]
2014-01-31 12:16 ` [U-Boot] [PATCH 3/6] usb:udc:samsung: Allow burst transfers for non EP0 endpints Lukasz Majewski
2014-01-31 12:16 ` [U-Boot] [PATCH 4/6] usb:udc:samsung: Zero copy approach for data passed to Samsung's UDC driver Lukasz Majewski
2014-02-01 2:55 ` Marek Vasut
2014-02-01 11:05 ` Lukasz Majewski
2014-02-01 22:55 ` Marek Vasut
2014-02-03 11:06 ` Lukasz Majewski
2014-02-03 18:11 ` Marek Vasut
2014-02-04 7:29 ` Lukasz Majewski
2014-02-04 20:21 ` Marek Vasut
2014-02-04 21:49 ` Lukasz Majewski
2014-02-05 2:35 ` Marek Vasut
2014-01-31 12:16 ` [U-Boot] [PATCH 5/6] usb:gadget:f_thor: Allocate request up to THOR_PACKET_SIZE not ep->maxpacket Lukasz Majewski
2014-01-31 12:16 ` [U-Boot] [PATCH 6/6] usb:gadget:f_thor: cosmetic: Remove debug memset Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 0/6] usb:samsung: Exynos4 SoC USB code improvements Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 1/6] usb:gadget:ums: Replace malloc calls with memalign to fix cache buffer alignment Lukasz Majewski
2014-02-06 1:20 ` Marek Vasut
2014-02-06 6:33 ` Lukasz Majewski
2014-02-06 6:41 ` Marek Vasut
2014-02-06 8:16 ` Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 2/6] usb:udc:samsung: Remove redundant cache operation from Samsung UDC driver Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 3/6] usb:udc:samsung: Allow burst transfers for non EP0 endpints Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 4/6] usb:udc:samsung: Zero copy approach for data passed to Samsung's UDC driver Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 5/6] usb:gadget:f_thor: Allocate request up to THOR_PACKET_SIZE not ep->maxpacket Lukasz Majewski
2014-02-05 9:10 ` [U-Boot] [PATCH v2 6/6] usb:gadget:f_thor: cosmetic: Remove debug memset Lukasz Majewski
2014-02-06 1:24 ` [U-Boot] [PATCH v2 0/6] usb:samsung: Exynos4 SoC USB code improvements Marek Vasut
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