Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-23 Thread Wolfram Sang
On Thu, Dec 11, 2014 at 02:26:41PM +0800, Jisheng Zhang wrote: > readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. > This introduces i2c read/write errors on Marvell BG2/BG2Q SoCs when there > are heavy L2 cache maintenance operations at the same time. > > The driver does no

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-13 Thread Jisheng Zhang
Dear Wolfram, On Tue, 13 Jan 2015 06:36:54 -0800 Wolfram Sang wrote: > > On Thu, Dec 11, 2014 at 02:26:41PM +0800, Jisheng Zhang wrote: > > readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. > > This introduces i2c read/write errors on Marvell BG2/BG2Q SoCs when there > >

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-13 Thread Baruch Siach
Hi Wolfram, On Tue, Jan 13, 2015 at 03:36:54PM +0100, Wolfram Sang wrote: > > The driver does not perform DMA, so it's safe to use the relaxed version. > > From another side, the relaxed io accessor macros are available on all > > architectures now, so we can use the relaxed versions instead. > >

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-13 Thread Wolfram Sang
On Thu, Dec 11, 2014 at 02:26:41PM +0800, Jisheng Zhang wrote: > readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. > This introduces i2c read/write errors on Marvell BG2/BG2Q SoCs when there > are heavy L2 cache maintenance operations at the same time. Reading this again, I

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-13 Thread Mika Westerberg
On Tue, Jan 13, 2015 at 12:52:05PM +0100, Wolfram Sang wrote: > On Fri, Dec 19, 2014 at 10:43:15AM +0800, Jisheng Zhang wrote: > > Dear all, > > > > Is there any issue I need to resolve so that the patch can be merged? > > Adding Mika to the loop. He uses the driver a lot (and knows other > peopl

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2015-01-13 Thread Wolfram Sang
On Fri, Dec 19, 2014 at 10:43:15AM +0800, Jisheng Zhang wrote: > Dear all, > > Is there any issue I need to resolve so that the patch can be merged? Adding Mika to the loop. He uses the driver a lot (and knows other people who do)... > On Wed, 10 Dec 2014 22:26:41 -0800 > Jisheng Zhang wrote:

Re: [PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2014-12-18 Thread Jisheng Zhang
Dear all, Is there any issue I need to resolve so that the patch can be merged? Thanks in advance, Jisheng On Wed, 10 Dec 2014 22:26:41 -0800 Jisheng Zhang wrote: > readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. > This introduces i2c read/write errors on Marvell BG2/B

[PATCH] i2c: designware: use {readl|writel}_relaxed instead of readl/writel

2014-12-10 Thread Jisheng Zhang
readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. This introduces i2c read/write errors on Marvell BG2/BG2Q SoCs when there are heavy L2 cache maintenance operations at the same time. The driver does not perform DMA, so it's safe to use the relaxed version. >From another sid