Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-03-01 Thread Boris Brezillon
On Wed, 1 Mar 2017 12:18:30 +0100 Frode Isaksen wrote: > On 01/03/2017 11:18, Boris Brezillon wrote: > > On Wed, 1 Mar 2017 11:09:57 +0100 > > Cyrille Pitchen wrote: > > > >> Le 28/02/2017 à 22:39, Richard Weinberger a écrit : > >>> Vignesh, > >>> > >>> Am 27.02.2017 um 13:08 schrieb Vignesh

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-03-01 Thread Vignesh R
On Wednesday 01 March 2017 03:39 PM, Cyrille Pitchen wrote: > Le 28/02/2017 à 22:39, Richard Weinberger a écrit : >> Vignesh, >> >> Am 27.02.2017 um 13:08 schrieb Vignesh R: >>> Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which >>> will end up in SPI layer. SPI core does tr

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-03-01 Thread Frode Isaksen
On 01/03/2017 11:18, Boris Brezillon wrote: > On Wed, 1 Mar 2017 11:09:57 +0100 > Cyrille Pitchen wrote: > >> Le 28/02/2017 à 22:39, Richard Weinberger a écrit : >>> Vignesh, >>> >>> Am 27.02.2017 um 13:08 schrieb Vignesh R: Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR lay

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-03-01 Thread Boris Brezillon
On Wed, 1 Mar 2017 11:09:57 +0100 Cyrille Pitchen wrote: > Le 28/02/2017 à 22:39, Richard Weinberger a écrit : > > Vignesh, > > > > Am 27.02.2017 um 13:08 schrieb Vignesh R: > >> Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which > >> will end up in SPI layer. SPI core do

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-03-01 Thread Cyrille Pitchen
Le 28/02/2017 à 22:39, Richard Weinberger a écrit : > Vignesh, > > Am 27.02.2017 um 13:08 schrieb Vignesh R: >> Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which >> will end up in SPI layer. SPI core does try to handle such buffers (see >> spi_map_buf()) by doing vmalloc_to_

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-02-28 Thread Vignesh R
On Wednesday 01 March 2017 03:09 AM, Richard Weinberger wrote: > Vignesh, > > Am 27.02.2017 um 13:08 schrieb Vignesh R: >> Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which >> will end up in SPI layer. SPI core does try to handle such buffers (see >> spi_map_buf()) by doin

Re: [RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-02-28 Thread Richard Weinberger
Vignesh, Am 27.02.2017 um 13:08 schrieb Vignesh R: > Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which > will end up in SPI layer. SPI core does try to handle such buffers (see > spi_map_buf()) by doing vmalloc_to_page() and creating scatterlist. But, > its known that this d

[RFC PATCH 1/2] mtd: spi-nor: Introduce bounce buffer to handle vmalloc'd buffers

2017-02-27 Thread Vignesh R
Filesystems like UBIFS may pass vmalloc'd buffers to SPI NOR layer which will end up in SPI layer. SPI core does try to handle such buffers (see spi_map_buf()) by doing vmalloc_to_page() and creating scatterlist. But, its known that this does not work well with VIVT/aliasing cache architectures. Th