Hi Mario,
On Fri, Mar 18, 2016 at 09:16:48AM +0100, mario.six@gdsys.cc wrote:
Hello,
I've been working on a QorIQ P1022 board (controlcenterd) to run the newest U-Boot on it, and I encountered some strange behavior.
During boot, we get these error messages
" ERROR: Cannot import environment: errno = 12
at common/env_common.c:221/env_import() *** Warning - import failed, using default environment
ERROR: Environment import failed: errno = 12
at common/env_common.c:123/set_default_env() ## Can't malloc 9 bytes "
After bisecting, I found out that the commit 4683b22 (mmc:fsl_esdhc invalidate dcache before read) apparently causes this. With the additional d-cache invalidations in place, malloc and free calls fail.
Now, after some experimenting, I found out that deactivating the d-cache invalidation when reading the first sector is enough; that is, if one replaces the first invalidation
" if (data->flags & MMC_DATA_READ) check_and_invalidate_dcache_range(cmd, data); "
with
" if (data->flags & MMC_DATA_READ && (cmd->cmdidx != MMC_CMD_READ_SINGLE_BLOCK || cmd->cmdarg != 0)) check_and_invalidate_dcache_range(cmd, data); "
in fsl_esdhc.c, it seems to work, but I have no idea why that is the case.
Any ideas would be greatly appreciated.
Before you chaning: " if (data->flags & MMC_DATA_READ) check_and_invalidate_dcache_range(cmd, data); "
can you please try this, https://patchwork.ozlabs.org/patch/511889/ and kindly give some feedback whether the patch can fix you issue or not?
I strongly agree that U-Boot should flow the Linux DMA flow to avoid potential write back and speculative read which may cause DMA data be polluted.
Anyway please first try first invalidate L2, then invalidate L1.
I plan to pick the upper patch or rework for DMA usage, but have not began the work (:
Thanks, Peng.
Best regards, Mario
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