On 17.02.2016 14:54, Sascha Hauer wrote:
Hi Dirk,
On Wed, Feb 17, 2016 at 02:42:33PM +0100, Dirk Behme wrote:
Hi Sascha,
On 17.02.2016 14:28, Sascha Hauer wrote:
This picks up a series sent by Anton Bondarenko last year. It
contains the remaining not yet upstreamed patches from Antons series
plus some more DMA related cleanup patches.
My mission was to hunt a bug in the DMA code path sometimes causing
an additional word in the RX FIFO which locked up the driver in the
next transfer. It turned out that this was no bug in the driver but
instead in the device tree: We used the wrong SDMA script for i.MX6.
The ECSPI cores are connected through the SPBA, so according to the
reference manual we need the shp/mcu scripts rather than the app/mcu
scripts.
Are you talking about what is known as "TKT238285 hardware issue"
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/spi/spi-imx.c?id=a02bb401f8ae264be782ee57d98bdd99f14c8022
I am aware of this issue, but I have no idea if this is the same or
another issue. It says:
For TKT238285 hardware issue which may cause txfifo store data twice can only
be caught on i.mx6dl, we use pio mode instead of DMA mode on i.mx6dl.
What I saw here is that there was one word more than expected in the RX
FIFO. Since both RX and TX FIFO act synchronously it could be that the
additional word in the RX FIFO was caused by an additional word in the
TX FIFO as described above.
The question behind all this is if we could drop
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/spi/spi-imx.c?id=a02bb401f8ae264be782ee57d98bdd99f14c8022
?
And/Or if/how we like to import the FSL workaround for TKT238285
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/commit/?h=imx_3.14.38_6qp_ga&id=646a751a4d1d0e227a762b461d9b8f92605c26b1
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/commit/?h=imx_3.14.38_6qp_ga&id=01f180af19a7d5c6f5abc51218be93ea4b5d68ff
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/commit/?h=imx_3.14.38_6qp_ga&id=321beb210ffb382b8b5378cbf4467f8986efd52f
?
Best regards
Dirk
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