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Date:   Mon, 29 Mar 2021 22:59:15 -0500
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Dikshita Agarwal <dikshita@codeaurora.org>
Cc:     linux-media@vger.kernel.org, stanimir.varbanov@linaro.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        vgarodia@codeaurora.org
Subject: Re: [PATCH v2] media: venus : hfi: add venus image info into smem
Message-ID: <YGKiExvhfdAhTw9/@builder.lan>
References: <1616740405-5085-1-git-send-email-dikshita@codeaurora.org>
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On Fri 26 Mar 01:33 CDT 2021, Dikshita Agarwal wrote:

> Fill fw version info into smem to be printed as part of
> soc info.
> 
> Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org>
> 
> Changes since v1:
>  adressed comments from stephen.
>  removed unwanted code.
> ---
>  drivers/media/platform/qcom/venus/hfi_msgs.c | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/hfi_msgs.c b/drivers/media/platform/qcom/venus/hfi_msgs.c
> index 06a1908..6b6d33c9 100644
> --- a/drivers/media/platform/qcom/venus/hfi_msgs.c
> +++ b/drivers/media/platform/qcom/venus/hfi_msgs.c
> @@ -6,6 +6,7 @@
>  #include <linux/hash.h>
>  #include <linux/list.h>
>  #include <linux/slab.h>
> +#include <linux/soc/qcom/smem.h>
>  #include <media/videobuf2-v4l2.h>
>  
>  #include "core.h"
> @@ -14,6 +15,10 @@
>  #include "hfi_msgs.h"
>  #include "hfi_parser.h"
>  
> +#define SMEM_IMG_VER_TBL 469
> +#define VER_STR_SZ	128
> +#define SMEM_IMG_INDEX_VENUS 14 * 128

14 is the index, 128 is the element size, so this is now an "offset".

> +
>  static void event_seq_changed(struct venus_core *core, struct venus_inst *inst,
>  			      struct hfi_msg_event_notify_pkt *pkt)
>  {
> @@ -239,15 +244,27 @@ static void
>  sys_get_prop_image_version(struct device *dev,
>  			   struct hfi_msg_sys_property_info_pkt *pkt)
>  {
> +	size_t smem_blk_sz = 0;

You shouldn't need to initialize smem_blk_sz if you check the return
value of qcom_smem_get() first.

> +	u8 *smem_tbl_ptr;
> +	u8 *img_ver;
>  	int req_bytes;
>  
>  	req_bytes = pkt->hdr.size - sizeof(*pkt);
>  
> -	if (req_bytes < 128 || !pkt->data[1] || pkt->num_properties > 1)
> +	if (req_bytes < VER_STR_SZ || !pkt->data[1] || pkt->num_properties > 1)
>  		/* bad packet */
>  		return;
>  
> -	dev_dbg(dev, VDBGL "F/W version: %s\n", (u8 *)&pkt->data[1]);
> +	img_ver = (u8 *)&pkt->data[1];
> +
> +	dev_dbg(dev, VDBGL "F/W version: %s\n", img_ver);
> +
> +	smem_tbl_ptr = qcom_smem_get(QCOM_SMEM_HOST_ANY,
> +				       SMEM_IMG_VER_TBL, &smem_blk_sz);

80 chars is just a guideline and this looks prettier if you avoid the
line wrap. That said, if you pick shorter names for smem_tbl_ptr and
smem_blk_sz you probably even have to worry.

> +	if ((SMEM_IMG_INDEX_VENUS + VER_STR_SZ) <= smem_blk_sz &&
> +	    smem_tbl_ptr)

In English you're trying to determine: "did qcom_smem_get() return a
valid pointer and is the item's size at least as big as we need".

So just write that in C:

	if (smem_tbl_ptr && smem_blk_sz >= SMEM_IMG_INDEX_VENUS + VER_STR_SZ)

> +		memcpy(smem_tbl_ptr + SMEM_IMG_INDEX_VENUS,
> +		       img_ver, VER_STR_SZ);

Again, please avoid the line wrap...

Regards,
Bjorn

>  }
>  
>  static void hfi_sys_property_info(struct venus_core *core,
> -- 
> 2.7.4
>