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Message-ID: <cbf3e828-77c9-8291-1328-7e876a8843d1@oss.qualcomm.com>
Date: Mon, 8 Dec 2025 15:55:51 +0530
From: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@....qualcomm.com>
To: Alexandru Gagniuc <mr.nuke.me@...il.com>, jjohnson@...nel.org,
ath11k@...ts.infradead.org, "Rob Herring (Arm)" <robh@...nel.org>
Cc: linux-wireless@...r.kernel.org, linux-kernel@...r.kernel.org,
stable@...r.kernel.org, Jeff Johnson <jeff.johnson@....qualcomm.com>
Subject: Re: [PATCH] wifi: ath11k: fix qmi memory allocation logic for CALDB
region
On 12/8/2025 3:38 PM, Vasanthakumar Thiagarajan wrote:
>
>
> On 12/6/2025 11:28 PM, Alexandru Gagniuc wrote:
>> Memory region assignment in ath11k_qmi_assign_target_mem_chunk()
>> assumes that:
>> 1. firmware will make a HOST_DDR_REGION_TYPE request, and
>> 2. this request is processed before CALDB_MEM_REGION_TYPE
>>
>> In this case CALDB_MEM_REGION_TYPE, can safely be assigned immediately
>> after the host region.
>>
>> However, if the HOST_DDR_REGION_TYPE request is not made, or the
>
> AFAICT, this is highly unlikely as HOST_DDR_REGION_TYPE will always be before
> CALDB_MEM_REGION_TYPE. >
>> reserved-memory node is not present, then res.start and res.end are 0,
>> and host_ddr_sz remains uninitialized. The physical address should
>> fall back to ATH11K_QMI_CALDB_ADDRESS. That doesn't happen:
>>
>> resource_size(&res) returns 1 for an empty resource, and thus the if
>> clause never takes the fallback path. ab->qmi.target_mem[idx].paddr
>> is assigned the uninitialized value of host_ddr_sz + 0 (res.start).
>>
>> Use "if (res.end > res.start)" for the predicate, which correctly
>> falls back to ATH11K_QMI_CALDB_ADDRESS.
>>
>> Fixes: 900730dc4705 ("wifi: ath: Use of_reserved_mem_region_to_resource() for
>> "memory-region"")
>>
>> Cc: stable@...r.kernel.org # v6.18
>> Signed-off-by: Alexandru Gagniuc <mr.nuke.me@...il.com>
>> ---
>> drivers/net/wireless/ath/ath11k/qmi.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath11k/qmi.c b/drivers/net/wireless/ath/ath11k/qmi.c
>> index aea56c38bf8f3..6cc26d1c1e2a4 100644
>> --- a/drivers/net/wireless/ath/ath11k/qmi.c
>> +++ b/drivers/net/wireless/ath/ath11k/qmi.c
>> @@ -2054,7 +2054,7 @@ static int ath11k_qmi_assign_target_mem_chunk(struct ath11k_base *ab)
>> return ret;
>> }
>> - if (res.end - res.start + 1 < ab->qmi.target_mem[i].size) {
>> + if (resource_size(&res) < ab->qmi.target_mem[i].size) {
>> ath11k_dbg(ab, ATH11K_DBG_QMI,
>> "fail to assign memory of sz\n");
>> return -EINVAL;
>> @@ -2086,7 +2086,7 @@ static int ath11k_qmi_assign_target_mem_chunk(struct ath11k_base *ab)
>> }
>> if (ath11k_core_coldboot_cal_support(ab)) {
>> - if (resource_size(&res)) {
>> + if (res.end > res.start) {
>> ab->qmi.target_mem[idx].paddr =
>> res.start + host_ddr_sz;
>> ab->qmi.target_mem[idx].iaddr =
>
> The rest looks good.
>
> Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@....qualcomm.com>
>
Well, since CALDB_MEM_REGION_TYPE will always come only after HOST_DDR_REGION_TYPE we'll
not be running into this issue in real deployment with ath11k firmware binaries available
in public.
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