Re: [PATCH v4 1/7] dma: qcom: bam_dma: Fix command element mask field for BAM v1.6.0+
From: Md Sadre Alam
Date: Tue Feb 10 2026 - 04:47:06 EST
Hi,
On 2/9/2026 5:36 PM, Krzysztof Kozlowski wrote:
On 09/02/2026 12:43, Md Sadre Alam wrote:You are right — the wording is misleading. I will update the commit message in next revision.
that use BAM v1.6.0+, because the current code sets mask=0xffffffff
for all commands. For read commands on newer BAM versions, this results
in the hardware interpreting the destination address as 0xf_xxxxxxxx
(invalid high memory) instead of the intended 0x0_xxxxxxxx address.
Fixed this issue by:
1. Updating the bam_cmd_element structure documentation to reflect the
dual purpose of the mask field
2. Modifying bam_prep_ce_le32() to set appropriate mask values based on
command type:
- For read commands: mask = 0 (32-bit addressing, upper bits = 0)
- For write commands: mask = 0xffffffff (traditional write mask)
3. Maintaining backward compatibility with older BAM versions
This fix enables proper NAND functionality on IPQ5424 and other platforms
using BAM v1.6.0+ while preserving compatibility with existing systems.
Fixes tag? CC-stable?
This patch is not fixing an existing commit. This is to address the
update in the newer version of the hardware.
Then "this fix" is misleading. Either you fix or not fix.
Thanks,
Alam.