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sopc2dts: cfi-flash & usb isp1362-hcd

Honored Contributor II

Hey nios2-community, 


I want to update my kernel from version 2.6.35 to version 3.3, but i have some problems integrating cfi-flash and usb. I'm working with a custom board similar to the neek-board and IP-Cores from Altera (mostly). Furthermore i'm using the neat tool: sopc2dts, which is a great help, but i'm not sure if i made some mistakes regarding the configuration of the device-tree. 


1) cfi-flash: Everytime i use flashcp or ioctls accessing the otp-register my system freezes. Nevertheless i can create a jffs2-filesystem on my older build and use that on my new build. So i can mount the jffs2 on kernel 3.3 and make everything with the files on it. The system just hangs when i access the flash directly over the flash-utilities and/or ioctls. (the ioctl is changing the mode of cfi-flash to MTD_OTP_FACTORY) 

I generated my device-tree with sopc2dts and the configuration regarding the cfi-flash seems to be just right. This is the entry about cfi-flash: 


cfi_flash: flash@0x4000000 { compatible = "ALTR,cfi_flash-9.0", "cfi-flash"; reg = < 0x04000000 0x02000000 >; bank-width = < 2 >; device-width = < 1 >; # address-cells = < 1 >; # size-cells = < 1 >; Linux-Kernel@0 { reg = < 0x00000000 0x00800000 >; }; //end Linux-Kernel@0 filesystem@1000000 { reg = < 0x01000000 0x01000000 >; }; //end filesystem@1000000 }; //end flash@0x4000000 (cfi_flash)My kernel-configuration is: 

-> MTD (x) 

-> MTD_OF_PARTS (x) 


-> MTD_BLOCK (x) 

-> RAM/ROM/Flash chip drivers 

-> MTD_CFI (x) 


-> MTD_OTP (x) 


-> Mapping drivers for chip access 


-> BLK_DEV (x) 


2) My USB-device isn't working anymore. It fails when checking the clkrdy signal at isp1362-hcd.c. This is really weird, because everything that was in the header-file nios2 in my older build is also in the device-tree. Here is the entry in my device-tree: 


isp1362_usb_controller: usb@0xa80 { compatible = "nxp,isp1362-1.0", "nxp,usb-isp1362"; reg = < 0x00000A80 0x00000008 0x00000B28 0x00000001 >; interrupt-parent = < &cpu_linux >; interrupts = < 10 11 >; }; //end usb@0xa80 (isp1362_usb_controller)I just added "nxp,usb-isp1362" to the compatible string. I think this has to happen otherwise uClinux can't load any driver at all. Btw here is the code snippet from the clkrdy check in isp1362-hcd.c: 


/* chip has been reset. First we need to see a clock */ t = jiffies + msecs_to_jiffies(timeout); while (!clkrdy && time_before_eq(jiffies, t)) { spin_lock_irqsave(&isp1362_hcd->lock, flags); clkrdy = isp1362_read_reg16(isp1362_hcd, HCuPINT) & HCuPINT_CLKRDY; spin_unlock_irqrestore(&isp1362_hcd->lock, flags); if (!clkrdy) msleep(4); } spin_lock_irqsave(&isp1362_hcd->lock, flags); isp1362_write_reg16(isp1362_hcd, HCuPINT, HCuPINT_CLKRDY); spin_unlock_irqrestore(&isp1362_hcd->lock, flags); if (!clkrdy) { pr_err("Clock not ready after %lums\n", timeout); ret = -ENODEV; } return ret;What am I missing here? I guess something is wrong with my device-tree but I checked a lot of entries in your newslist. I don't know what could be wrong here, so any help would be great. 


For information purpose I attached our sopcinfo file. Thanks in advance. 


kind regards, 

Tobias Biehl
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1 Reply
Honored Contributor II

Hey guys, 


my cfi-flash is now working again :) 


I dont know why flashcp froze my system. I simply made a new kernel-configuration and now it works perfect. I guess I had messed up my config somewhere. 


Nevertheless accessing the otp-register from my cfi-flash was still causing a kernel-panic, Null Pointer reference in particular. I looked through the code and I stumbled on something. When I'm calling ioctl with OTPSELECT to change the mode, the function otp_select_filemode is called in mtdchar.c. There is a call to another function: 


/* * Make a fake call to mtd_read_fact_prot_reg() to check if OTP * operations are supported. */ if (mtd_read_fact_prot_reg(mtd, -1, -1, &retlen, NULL) == -EOPNOTSUP P) return -EOPNOTSUPP; I dont know if its really a bug, but thats the cause of my kernel-panic. the 3rd parameter is len with type size_t. size_t is defined to be __kernel_size_t which is defined as unsigned long. So this would cause an overflow of len. In read_fact_prot_reg() is another call to the function cfi_intelext_otp_walk, which does mostly all the work except the actual read from the otp-register. This does do_otp_read (action points to that function). The code-lines: 


while (len > 0) { /* flash geometry fixup */ data_offset = reg_prot_offset + 1; data_offset *= cfi->interleave * cfi->device_type; reg_prot_offset *= cfi->interleave * cfi->device_type; reg_fact_size *= cfi->interleave; reg_user_size *= cfi->interleave; if (user_regs) { groups = reg_user_groups; groupsize = reg_user_size; /* skip over factory reg area */ groupno = reg_fact_groups; data_offset += reg_fact_groups * reg_fact_size; } else { groups = reg_fact_groups; groupsize = reg_fact_size; groupno = 0; } while (len > 0 && groups > 0) { if (!action) { } else if (from >= groupsize) { from -= groupsize; data_offset += groupsize; } else { int size = groupsize; data_offset += from; size -= from; from = 0; if (size > len) size = len; ret = action(map, chip, data_offset, buf, size, reg_prot_offset, groupno, groupsize); if (ret < 0) return ret; buf += size; len -= size; *retlen += size; data_offset += size; } groupno++; groups--; } well, len is positive, groups will be 1. from is actually -1, so else. And there is a call action() with our buf which is NULL. In there the function tries to copy data to that location -> kernel panic 


I solved this problem changing the 3rd parameter -1 to 0. I guess this was the idea afterall, that the function just checks if there are otp-register and not trying to read them. 


Maybe I wrote too much here, but now you guys can easily track down this one, if its really a bug. I guess it is, correct me if I'm wrong =) 


And my usb is still not working properly, so if anybody knows something there, i would appreciate it. 


kind regards, 

Tobias Biehl