[PATCH v4] bus: mhi: host: don't free bhie tables during suspend/hibernation

[Baochen Qiang]

On 5/6/2025 10:49 PM, Muhammad Usama Anjum wrote:
> Fix dma_direct_alloc() failure at resume time during bhie_table
> allocation because of memory pressure. There is a report where at
> resume time, the memory from the dma doesn't get allocated and MHI
> fails to re-initialize.
> 
> To fix it, don't free the memory at power down during suspend /
> hibernation. Instead, use the same allocated memory again after every
> resume / hibernation. This patch has been tested with resume and
> hibernation both.
> 
> The rddm is of constant size for a given hardware. While the fbc_image
> size depends on the firmware. If the firmware changes, we'll free and
> allocate new memory for it.
> 
> Tested-on: WCN6855 WLAN.HSP.1.1-03926.13-QCAHSPSWPL_V2_SILICONZ_CE-2.52297.6
> 
> Signed-off-by: Muhammad Usama Anjum <usama.anjum at collabora.com>

with WLAN firmware unchanged, suspend/resume is working well:

Tested-on: WCN7850 hw2.0 WLAN.HMT.1.1.c5-00284-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Tested-by: Baochen Qiang <quic_bqiang at quicinc.com>