[U-Boot] x86: SPI flash broken with SPI NOR

[Vignesh Raghavendra]

On 05/06/19 8:17 PM, Bin Meng wrote:
> Hi Vignesh,
> 
> On Wed, Jun 5, 2019 at 9:40 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>>
>> Hi Vignesh,
>>
>> On Sat, Apr 27, 2019 at 12:26 AM Vignesh Raghavendra <vigneshr at ti.com> wrote:
>>>
>>> Bin,
>>>
>>> On 26/04/19 7:33 PM, Bin Meng wrote:
>>>> Hi Simon,
>>>>
>>>> On Fri, Apr 26, 2019 at 7:26 AM Simon Glass <sjg at chromium.org> wrote:
>>>>>
>>>>> Hi Bin,
>>>>>
>>>>> I find that 'sf test 0 1000' does not work anymore since this commit:
>>>>>
>>>>> c4e8862308 mtd: spi: Switch to new SPI NOR framework
>>>>>
>>>>> Have you seen any problems? This seems to prevent proper SPI flash writing (not sure about reading).
>>>>
>>>> Yes, this seems to be broken. I just tested it on MinnowMax.
>>>>
>>>
>>> What is the flash part on this board?
>>>
>>>
>>>> 'sf probe' does not succeed anymore.
>>>>
>>>
>>> Could you enable all debug prints in spi_mem_exec_op() in spi-mem.c:
>>> https://elixir.bootlin.com/u-boot/latest/source/drivers/spi/spi-mem.c#L376
>>>
>>> And the post the full log here. If the log is too big please paste it to pastebin.ubuntu.com
>>>
>>> Also please apply http://patchwork.ozlabs.org/patch/1090121/ on top of latest tree before doing any write to flash
>>>
>>> Sorry for the trouble.
>>>
>>
>> Sorry for the long delay. I finally got time to look into this.
>>
>> However with the latest u-boot/master, the SPI flash seems to work
>> again on Intel MinnowMax. Did you recall anything changes in the
>> spi-nor recently?
> 
> The thing I know is:
> 
> v2019.07-rc1: Intel ich-spi driver was broken
> v2019.07-rc2: Intel ich-spi driver worked again
> 
> So I did a 'git bisect', although I used it in a reverse direction :)
> 
> This is the commit that makes the Intel ich-spi driver work again.


That's great to know! There is a patch on ML to convert ich-spi to
spi-mem which should make driver much simpler[1]. It would be great to
have that patch tested and merged.

[]1https://patchwork.ozlabs.org/patch/1072475/

Regards
Vignesh
> 
> commit 60e2bf46784ebbd30ff29b3d3c7c97e56b11e86a
> Author: Weijie Gao <weijie.gao at mediatek.com>
> Date:   Fri Apr 26 17:22:19 2019 +0800
> 
>     mtd: spi-nor: fix page program issue when using spi-mem driver
> 
>     Some SPI controllers can't write nor->page_size bytes in a single step
>     because their TX FIFO is too small, but when that happens we should
>     make sure a WRITE_EN command before each write access and READ_SR command
>     after each write access is issued.
> 
>     We should allow nor->write() to return a size that is smaller than the
>     requested write size to gracefully handle this case.
> 
>     Also, the spi_nor_write_data() should return the actual number of bytes
>     that were written during the spi_mem_exec_op() operation.
> 
>     This patch is a combination of two commits backported from kernel:
> 
>       commit 630d6bd8a3b4 ("mtd: spi-nor: Support controllers with limit ...")
>       commit 3baa8ec88c2f ("mtd: devices: m25p80: Make sure WRITE_EN is ...")
> 
>     Cc: Vignesh R <vigneshr at ti.com>
>     Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
>     Acked-by: Vignesh R <vigneshr at ti.com>
>     Tested-by: Shyam Saini <shyam.saini at amarulasolutions.com> # microzed
>     Acked-by: Jagan Teki <jagan at amarulasolutions.com>
> 
> Hi Simon,
> 
> Could you please confirm that on the Chromebook?
> 
> Regards,
> Bin
> 

-- 
Regards
Vignesh