linux.git/drivers/interconnect/mediatek, branch v6.12.80 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git interconnect: mediatek: Aggregate bandwidth with saturating add 2026-03-04T12:20:28+00:00 Nicolas Frattaroli nicolas.frattaroli@collabora.com 2025-11-24T11:07:02+00:00 525858eb00fb26c59201a4010688f968cc720caa [ Upstream commit 6ffd02b82243d9907b5f5d2c7a2fc6a62669eece ] By using a regular non-overflow-checking add, the MediaTek icc-emi driver will happy wrap at U32_MAX + 1 to 0. As it's common for the interconnect core to fill in INT_MAX values, this is not a hypothetical situation, but something that actually happens in regular use. This would be pretty disasterous if anything used this driver. Replace the addition with an overflow-checked addition from overflow.h, and saturate to U32_MAX if an overflow is detected. Fixes: b45293799f75 ("interconnect: mediatek: Add MediaTek MT8183/8195 EMI Interconnect driver") Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com> Link: https://lore.kernel.org/r/20251124-mt8196-dvfsrc-v2-13-d9c1334db9f3@collabora.com Signed-off-by: Georgi Djakov <djakov@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6ffd02b82243d9907b5f5d2c7a2fc6a62669eece ]

By using a regular non-overflow-checking add, the MediaTek icc-emi
driver will happy wrap at U32_MAX + 1 to 0. As it's common for the
interconnect core to fill in INT_MAX values, this is not a hypothetical
situation, but something that actually happens in regular use. This
would be pretty disasterous if anything used this driver.

Replace the addition with an overflow-checked addition from overflow.h,
and saturate to U32_MAX if an overflow is detected.

Fixes: b45293799f75 ("interconnect: mediatek: Add MediaTek MT8183/8195 EMI Interconnect driver")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20251124-mt8196-dvfsrc-v2-13-d9c1334db9f3@collabora.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
interconnect: mediatek: Don't hijack parent device 2026-03-04T12:20:28+00:00 Nicolas Frattaroli nicolas.frattaroli@collabora.com 2025-11-24T11:07:01+00:00 5d7c7c54b6a5c9de740742cf5cc731abca97b671 [ Upstream commit 510f8214440c553e81774c5822437ccf154e9e38 ] If the intention is that users of the interconnect declare their relationship to the child icc_emi node of the dvfsrc controller, then this code never worked. That's because it uses the parent dvfsrc device as the device it passes to the interconnect core framework, which means all the OF parsing is broken. Use the actual device instead, and pass the dvfsrc parent into the dvfsrc calls. Fixes: b45293799f75 ("interconnect: mediatek: Add MediaTek MT8183/8195 EMI Interconnect driver") Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com> Link: https://lore.kernel.org/r/20251124-mt8196-dvfsrc-v2-12-d9c1334db9f3@collabora.com Signed-off-by: Georgi Djakov <djakov@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 510f8214440c553e81774c5822437ccf154e9e38 ]

If the intention is that users of the interconnect declare their
relationship to the child icc_emi node of the dvfsrc controller, then
this code never worked. That's because it uses the parent dvfsrc device
as the device it passes to the interconnect core framework, which means
all the OF parsing is broken.

Use the actual device instead, and pass the dvfsrc parent into the
dvfsrc calls.

Fixes: b45293799f75 ("interconnect: mediatek: Add MediaTek MT8183/8195 EMI Interconnect driver")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20251124-mt8196-dvfsrc-v2-12-d9c1334db9f3@collabora.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
interconnect: mediatek: remove unneeded semicolon 2024-06-24T12:07:25+00:00 Jiapeng Chong jiapeng.chong@linux.alibaba.com 2024-06-24T02:53:26+00:00 9265ea04a7b501e45134de13c0cbb81e897adf33 No functional modification involved. ./drivers/interconnect/mediatek/icc-emi.c:71:2-3: Unneeded semicolon. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9401 Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/20240624025326.69551-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Georgi Djakov <djakov@kernel.org> 
No functional modification involved.

./drivers/interconnect/mediatek/icc-emi.c:71:2-3: Unneeded semicolon.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9401
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240624025326.69551-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
interconnect: mediatek: Add MediaTek MT8183/8195 EMI Interconnect driver 2024-06-13T11:31:43+00:00 AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com 2024-06-10T08:57:35+00:00 b45293799f75e002d5da9d9e3d2a5c418f492fd0 Add an interconnect driver for the External Memory Interface (EMI), voting for bus bandwidth over the Dynamic Voltage and Frequency Scaling Resource Collector (DVFSRC). ICC provider ICC Nodes ---- ---- --------- |CPU | |--- |VPU | ----- | |----- ---- | ---- |DRAM |--|DRAM | ---- | ---- | |--|scheduler|----- |GPU | |--- |DISP| | |--|(EMI) | ---- | ---- | |--| | ----- | ---- ----- | |----- |MMSYS|--|--- |VDEC| --------- ----- | ---- /|\ | ---- |change DRAM freq |--- |VENC| ---------- | ---- | DVFSR | | | | | ---- ---------- |--- |IMG | | ---- | ---- |--- |CAM | ---- Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Link: https://lore.kernel.org/r/20240610085735.147134-8-angelogioacchino.delregno@collabora.com Signed-off-by: Georgi Djakov <djakov@kernel.org> 
Add an interconnect driver for the External Memory Interface (EMI),
voting for bus bandwidth over the Dynamic Voltage and Frequency Scaling
Resource Collector (DVFSRC).

             ICC provider         ICC Nodes
                              ----          ----
             ---------       |CPU |   |--- |VPU |
    -----   |         |-----  ----    |     ----
   |DRAM |--|DRAM     |       ----    |     ----
   |     |--|scheduler|----- |GPU |   |--- |DISP|
   |     |--|(EMI)    |       ----    |     ----
   |     |--|         |       -----   |     ----
    -----   |         |----- |MMSYS|--|--- |VDEC|
             ---------        -----   |     ----
               /|\                    |     ----
                |change DRAM freq     |--- |VENC|
             ----------               |     ----
            |  DVFSR   |              |
            |          |              |     ----
             ----------               |--- |IMG |
                                      |     ----
                                      |     ----
                                      |--- |CAM |
                                            ----

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240610085735.147134-8-angelogioacchino.delregno@collabora.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>