Re: [PATCH 1/2] irqchip/qcom-pdc: don't read version register if it is not available

From: Maulik Shah (mkshah)
Date: Mon Aug 28 2023 - 05:37:50 EST


Hi Dmitry,

This patch may be useful if there was a case where some PDCs don't have version register populated/available,
In all PDC versions, version register is always available but due to reg size not good enough in device tree for SM8150 it failed to read.

reg size in device node must be expanded if its too small to access all registers and i think
additional check in driver to check if size is good enough would not be of much use.

Thanks,
Maulik

On 8/26/2023 3:05 AM, Dmitry Baryshkov wrote:

On Qualcomm SM8150 the PDC resource has size 0x400. When PDC driver
tries to read the version register (0x1000), it reads past the end of
this resource, causing kernel crash.

Check the size of PDC resource before reading the PDC_VERSION register.

Fixes: bc82cc42644b ("irqchip/qcom-pdc: Add support for v3.2 HW")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>