From: Ben Skeggs bskeggs@redhat.com
commit 752a281032b2d6f4564be827e082bde6f7d2fd4f upstream.
This was completely bogus before, using maximum DCB device index rather than maximum AUX ID to size the buffer that stores event refcounts.
*Pretty* unlikely to have been an actual problem on most configurations, that is, unless you've got one of the rare boards that have off-chip DP.
There, it'll likely crash.
Cc: stable@vger.kernel.org # 6.4+ Signed-off-by: Ben Skeggs bskeggs@redhat.com Reviewed-by: Karol Herbst kherbst@redhat.com Signed-off-by: Karol Herbst kherbst@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20230719044051.6975-1-skeggsb@... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h | 4 ++-- drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c | 11 +++++++++-- 2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h index 40a1065ae626..ef441dfdea09 100644 --- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h +++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h @@ -16,7 +16,7 @@ struct nvkm_i2c_bus { const struct nvkm_i2c_bus_func *func; struct nvkm_i2c_pad *pad; #define NVKM_I2C_BUS_CCB(n) /* 'n' is ccb index */ (n) -#define NVKM_I2C_BUS_EXT(n) /* 'n' is dcb external encoder type */ ((n) + 0x100) +#define NVKM_I2C_BUS_EXT(n) /* 'n' is dcb external encoder type */ ((n) + 0x10) #define NVKM_I2C_BUS_PRI /* ccb primary comm. port */ -1 #define NVKM_I2C_BUS_SEC /* ccb secondary comm. port */ -2 int id; @@ -38,7 +38,7 @@ struct nvkm_i2c_aux { const struct nvkm_i2c_aux_func *func; struct nvkm_i2c_pad *pad; #define NVKM_I2C_AUX_CCB(n) /* 'n' is ccb index */ (n) -#define NVKM_I2C_AUX_EXT(n) /* 'n' is dcb external encoder type */ ((n) + 0x100) +#define NVKM_I2C_AUX_EXT(n) /* 'n' is dcb external encoder type */ ((n) + 0x10) int id;
struct mutex mutex; diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c index 976539de4220..731b2f68d3db 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c @@ -260,10 +260,11 @@ nvkm_i2c_new_(const struct nvkm_i2c_func *func, struct nvkm_device *device, { struct nvkm_bios *bios = device->bios; struct nvkm_i2c *i2c; + struct nvkm_i2c_aux *aux; struct dcb_i2c_entry ccbE; struct dcb_output dcbE; u8 ver, hdr; - int ret, i; + int ret, i, ids;
if (!(i2c = *pi2c = kzalloc(sizeof(*i2c), GFP_KERNEL))) return -ENOMEM; @@ -406,5 +407,11 @@ nvkm_i2c_new_(const struct nvkm_i2c_func *func, struct nvkm_device *device, } }
- return nvkm_event_init(&nvkm_i2c_intr_func, &i2c->subdev, 4, i, &i2c->event); + ids = 0; + list_for_each_entry(aux, &i2c->aux, head) + ids = max(ids, aux->id + 1); + if (!ids) + return 0; + + return nvkm_event_init(&nvkm_i2c_intr_func, &i2c->subdev, 4, ids, &i2c->event); }