On 26/10/2024 23:42, Dmitry Baryshkov wrote:
From: Naman Jain <quic_namajain@xxxxxxxxxxx>
Add logic for alignment of address for reading in qfprom driver to avoid
NOC error issues due to unaligned access. The problem manifests on the
SAR2130P platform, but in msm-5.x kernels the fix is applied
Is this only issue with SAR2130P?
uncoditionally. Follow this approach and uncoditionally perform aligned
reads.
If there is a need of having proper register alignment this should go as
part of the nvmem_config->stride and word_size configuration and not in
reg_read callbacks.
--srini
Fixes: 4ab11996b489 ("nvmem: qfprom: Add Qualcomm QFPROM support.")
Signed-off-by: Naman Jain <quic_namajain@xxxxxxxxxxx>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/nvmem/qfprom.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c
index 116a39e804c70b4a0374f8ea3ac6ba1dd612109d..cad319e7bfcf34c9b9ab15eb331efda822699cce 100644
--- a/drivers/nvmem/qfprom.c
+++ b/drivers/nvmem/qfprom.c
@@ -322,15 +322,28 @@ static int qfprom_reg_read(void *context,
{
struct qfprom_priv *priv = context;
u8 *val = _val;
- int i = 0, words = bytes;
+ int buf_start, buf_end, index, i = 0;
void __iomem *base = priv->qfpcorrected;
+ char *buffer = NULL;
+ u32 read_val;
if (read_raw_data && priv->qfpraw)
base = priv->qfpraw;
+ buf_start = ALIGN_DOWN(reg, 4);
+ buf_end = ALIGN(reg + bytes, 4);
+ buffer = kzalloc(buf_end - buf_start, GFP_KERNEL);
+ if (!buffer) {
+ pr_err("memory allocation failed in %s\n", __func__);
+ return -ENOMEM;
+ }
- while (words--)
- *val++ = readb(base + reg + i++);
+ for (index = buf_start; index < buf_end; index += 4, i += 4) {
+ read_val = readl_relaxed(base + index);
+ memcpy(buffer + i, &read_val, 4);
+ }
+ memcpy(val, buffer + reg % 4, bytes);
+ kfree(buffer);
return 0;
}
