[U-Boot] [RFC] mmc: fsl_esdhc: fix misaligned cache operation warning

When using gzwrite to eMMC on an i.MX6Q board, the following warning occurs repeatedly: CACHE: Misaligned operation at range [4fd63318, 4fe63318]
I tried to cache-line align the start and end parameter for flush_dcache_range in esdhc_setup_data. (Same approach as in https://patchwork.ozlabs.org/patch/656470/)
After that, the "Misaligned operation" error message disappeared and everything still works for me.
But is this safe and should I send the patch again with [PATCH] ?
Signed-off-by: Clemens Gruber clemens.gruber@pqgruber.com --- drivers/mmc/fsl_esdhc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 103b32e..f40b424 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -222,6 +222,7 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data) dma_addr_t addr; #endif uint wml_value; + ulong start, end;
wml_value = data->blocksize/4;
@@ -243,9 +244,11 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data) #endif } else { #ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO - flush_dcache_range((ulong)data->src, - (ulong)data->src+data->blocks - *data->blocksize); + start = (ulong)data->src; + start &= ~(CONFIG_SYS_CACHELINE_SIZE - 1); + end = ALIGN((ulong)data->src + data->blocks * data->blocksize, + CONFIG_SYS_CACHELINE_SIZE); + flush_dcache_range(start, end); #endif if (wml_value > WML_WR_WML_MAX) wml_value = WML_WR_WML_MAX_VAL;

On 2016-08-27 15:39, Clemens Gruber wrote:
When using gzwrite to eMMC on an i.MX6Q board, the following warning occurs repeatedly: CACHE: Misaligned operation at range [4fd63318, 4fe63318]
I tried to cache-line align the start and end parameter for flush_dcache_range in esdhc_setup_data. (Same approach as in https://patchwork.ozlabs.org/patch/656470/)
After that, the "Misaligned operation" error message disappeared and everything still works for me.
But is this safe and should I send the patch again with [PATCH] ?
Signed-off-by: Clemens Gruber clemens.gruber@pqgruber.com
drivers/mmc/fsl_esdhc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 103b32e..f40b424 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -222,6 +222,7 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data) dma_addr_t addr; #endif uint wml_value;
ulong start, end;
wml_value = data->blocksize/4;
@@ -243,9 +244,11 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data) #endif } else { #ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO
flush_dcache_range((ulong)data->src,
(ulong)data->src+data->blocks
*data->blocksize);
start = (ulong)data->src;
start &= ~(CONFIG_SYS_CACHELINE_SIZE - 1);
end = ALIGN((ulong)data->src + data->blocks * data->blocksize,
CONFIG_SYS_CACHELINE_SIZE);
flush_dcache_range(start, end);
Hm, that seems dangerous to me, especially the src rounding...
Not sure where that memory gets aligned, but I guess we should use memalign and align the length to cache size or the like...
-- Stefan
#endif if (wml_value > WML_WR_WML_MAX) wml_value = WML_WR_WML_MAX_VAL;

Hi,
On Sun, Aug 28, 2016 at 04:55:36PM -0700, Stefan Agner wrote:
Hm, that seems dangerous to me, especially the src rounding...
Not sure where that memory gets aligned, but I guess we should use memalign and align the length to cache size or the like...
Yes, you are right. I looked into this some more and found the source of the problem is actually in lib/gunzip.c and not the flush_dcache_range call in fsl_esdhc.c. I sent a new patch to cache-align the memory allocation in gzwrite.
Regards, Clemens
participants (2)
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Clemens Gruber
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Stefan Agner