Re: mtd raw nand denali.c broken for Intel/Altera Cyclone V

[Marek Vasut <marek.vasut@gmail.com>]

On 1/10/20 5:46 PM, Tim Sander wrote:
> Hi Masahiro Yamada

Hi,

> Sorry for the large delay. I have seen the patches at 
> https://lists.infradead.org/pipermail/linux-mtd/2019-December/092852.html
> Seem to resolve the question about the spare_area_skip_bytes register.
> 
> I have now set the register to 2 which seems to be the right choice on an Intel  
> SocFPGA. But still i am out of luck trying to boot 5.4.5-rt3 or 5.5-rc5. I get the 
> following messages during bootup booting:
> [    1.825590] denali-nand-dt ff900000.nand: timeout while waiting for irq 0x1000
> [    1.832936] denali-nand-dt: probe of ff900000.nand failed with error -5
> 
> But the commit c19e31d0a32dd 2017-06-13 22:45:38 predates the 4.19 kernel
> release (Mon Oct 22 07:37:37 2018). So it seems there is not an obvious commit
> which is causing the problem. Looking at the changes it might be that the timing
> calculations in the driver changed which might also lead to a similar error.
> 
> I am booting via NFS the bootloader is placed in NOR flash.  The corresponding 
> nand dts entry is updated to the new format and looks like this:
>                 nand@ff900000 {
>                         #address-cells = <0x1>;
>                         #size-cells = <0x0>;
>                         compatible = "altr,socfpga-denali-nand";
>                         reg = <0xff900000 0x100000 0xffb80000 0x10000>;
>                         reg-names = "nand_data", "denali_reg";
>                         interrupts = <0x0 0x90 0x4>;
>                         clocks = <0x2d 0x1e 0x2e>;
>                         clock-names = "nand", "nand_x", "ecc";
>                         resets = <0x6 0x24>;
>                         status = "okay";
>                         nand@0 {
>                                 reg = <0x0>;
>                                 #address-cells = <0x1>;
>                                 #size-cells = <0x1>;
>                                 partition@0 {
>                                         label = "work";
>                                         reg = <0x0 0x10000000>;
>                                 };
>                         };
>                 };
> 
> The last kernel i am able to boot is 4.19.10. I have tried booting:
> 5.1.21, 5.2.9, 5.3-rc8, 5.4.5-rt3 and 5.5-rc5. They all failed. Unfortunately the 
> range is quite large for bisecting the problem. It also occurred to me that
> all the platforms with Intel Cyclone V in mainline are development boards
> which boot from SD-card not exhibiting this problem on their default boot path.

There are also patches for U-Boot which you need to get this whole thing
working, unless you have reset support for the Denali NAND in mainline
Linux. See

https://patchwork.ozlabs.org/project/uboot/list/?series=152289

Sadly, all of the efforts thus far crashed on various review pushback.

> Best regards
> Tim
> 
> PS: Here is some snippet from an older mail i didn't sent to the list yet which
> might be superseded by now:
> To get into this matter i started reading the "Intel Cyclone V HPS TRM" 
> Section 13-20 Preserving Bad Block Markers:
> "You can configure the NAND flash controller to skip over a specified number of 
> bytes when it writes the last sector in a page to the spare area. This option 
> write the desired offset to the spare_area_skip_bytes register in the config 
> group. For example, if the device page size is 2 KB, and the device 
> area, set the spare_area_skip_bytes register to 2. When the flash controller 
> writes the last sector of the page that overlaps with the spare area, it 
> spare_area_skip_bytes must be an even number. For example, if the bad block 
> marker is a single byte, set spare_area_skip_bytes to 2."
> 
> 
> 
> 
> 


-- 
Best regards,
Marek Vasut