Re: [PATCH 1/2] media: siano: don't use GFP_DMA

[Tomoki Sekiyama <tomoki.sekiyama@gmail.com>]

2018-05-06 18:21 GMT+09:00 Mauro Carvalho Chehab <mchehab+samsung@kernel.org>:
> Em Sun, 6 May 2018 08:05:05 +0900
> Tomoki Sekiyama <tomoki.sekiyama@gmail.com> escreveu:
>
>> 2018/5/6 1:09 Mauro Carvalho Chehab <mchehab+samsung@kernel.org>:
>>
>> > I can't think on a single reason why this driver would be using
>> > GFP_DMA. The typical usage is as an USB driver. Any DMA restrictions
>> > should be handled inside the HCI driver, if any.
>> >
>>
>> siano driver supports SDIO (implemented
>> in drivers/media/mmc/siano/smssdio.c) as well as USB.
>> It looks like using sdio_memcpy_toio() to DMA transfer. I think that's why
>> it is using GFP_DMA.
>
> Good point. I always forget about the mmc variant, as I don't
> have any hardware to test.
>
> The best seems to add a new parameter to sms core register
> function, allowing it to use extra gfp flags, and pass it only
> for the SDIO variant.
>
> Patch enclosed.

I have confirmed that the USB stick works without GFP_DMA.
The patch LGTM.

Thanks,
Tomoki

> Regards,
> Mauro
>
> [PATCH 1/2 v2] media: siano: use GFP_DMA only for smssdio
>
> Right now, the Siano's core uses GFP_DMA for both USB and
> SDIO variants of the driver. There's no reason to use it
> for USB. So, pass GFP_DMA as a parameter during sms core
> register.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
>
> diff --git a/drivers/media/common/siano/smscoreapi.c b/drivers/media/common/siano/smscoreapi.c
> index b5dcc6d1fe90..9ed7afa7b2ae 100644
> --- a/drivers/media/common/siano/smscoreapi.c
> +++ b/drivers/media/common/siano/smscoreapi.c
> @@ -649,6 +649,7 @@ smscore_buffer_t *smscore_createbuffer(u8 *buffer, void *common_buffer,
>   */
>  int smscore_register_device(struct smsdevice_params_t *params,
>                             struct smscore_device_t **coredev,
> +                           gfp_t gfp_buf_flags,
>                             void *mdev)
>  {
>         struct smscore_device_t *dev;
> @@ -661,6 +662,7 @@ int smscore_register_device(struct smsdevice_params_t *params,
>  #ifdef CONFIG_MEDIA_CONTROLLER_DVB
>         dev->media_dev = mdev;
>  #endif
> +       dev->gfp_buf_flags = gfp_buf_flags;
>
>         /* init list entry so it could be safe in smscore_unregister_device */
>         INIT_LIST_HEAD(&dev->entry);
> @@ -697,7 +699,7 @@ int smscore_register_device(struct smsdevice_params_t *params,
>                 buffer = dma_alloc_coherent(params->device,
>                                             dev->common_buffer_size,
>                                             &dev->common_buffer_phys,
> -                                           GFP_KERNEL | GFP_DMA);
> +                                           GFP_KERNEL | dev->gfp_buf_flags);
>         if (!buffer) {
>                 smscore_unregister_device(dev);
>                 return -ENOMEM;
> @@ -792,7 +794,7 @@ static int smscore_init_ir(struct smscore_device_t *coredev)
>                 else {
>                         buffer = kmalloc(sizeof(struct sms_msg_data2) +
>                                                 SMS_DMA_ALIGNMENT,
> -                                               GFP_KERNEL | GFP_DMA);
> +                                               GFP_KERNEL | coredev->gfp_buf_flags);
>                         if (buffer) {
>                                 struct sms_msg_data2 *msg =
>                                 (struct sms_msg_data2 *)
> @@ -933,7 +935,7 @@ static int smscore_load_firmware_family2(struct smscore_device_t *coredev,
>         }
>
>         /* PAGE_SIZE buffer shall be enough and dma aligned */
> -       msg = kmalloc(PAGE_SIZE, GFP_KERNEL | GFP_DMA);
> +       msg = kmalloc(PAGE_SIZE, GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!msg)
>                 return -ENOMEM;
>
> @@ -1168,7 +1170,7 @@ static int smscore_load_firmware_from_file(struct smscore_device_t *coredev,
>         }
>         pr_debug("read fw %s, buffer size=0x%zx\n", fw_filename, fw->size);
>         fw_buf = kmalloc(ALIGN(fw->size + sizeof(struct sms_firmware),
> -                        SMS_ALLOC_ALIGNMENT), GFP_KERNEL | GFP_DMA);
> +                        SMS_ALLOC_ALIGNMENT), GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!fw_buf) {
>                 pr_err("failed to allocate firmware buffer\n");
>                 rc = -ENOMEM;
> @@ -1260,7 +1262,7 @@ EXPORT_SYMBOL_GPL(smscore_unregister_device);
>  static int smscore_detect_mode(struct smscore_device_t *coredev)
>  {
>         void *buffer = kmalloc(sizeof(struct sms_msg_hdr) + SMS_DMA_ALIGNMENT,
> -                              GFP_KERNEL | GFP_DMA);
> +                              GFP_KERNEL | coredev->gfp_buf_flags);
>         struct sms_msg_hdr *msg =
>                 (struct sms_msg_hdr *) SMS_ALIGN_ADDRESS(buffer);
>         int rc;
> @@ -1309,7 +1311,7 @@ static int smscore_init_device(struct smscore_device_t *coredev, int mode)
>         int rc = 0;
>
>         buffer = kmalloc(sizeof(struct sms_msg_data) +
> -                       SMS_DMA_ALIGNMENT, GFP_KERNEL | GFP_DMA);
> +                       SMS_DMA_ALIGNMENT, GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!buffer)
>                 return -ENOMEM;
>
> @@ -1398,7 +1400,7 @@ int smscore_set_device_mode(struct smscore_device_t *coredev, int mode)
>                 coredev->device_flags &= ~SMS_DEVICE_NOT_READY;
>
>                 buffer = kmalloc(sizeof(struct sms_msg_data) +
> -                                SMS_DMA_ALIGNMENT, GFP_KERNEL | GFP_DMA);
> +                                SMS_DMA_ALIGNMENT, GFP_KERNEL | coredev->gfp_buf_flags);
>                 if (buffer) {
>                         struct sms_msg_data *msg = (struct sms_msg_data *) SMS_ALIGN_ADDRESS(buffer);
>
> @@ -1971,7 +1973,7 @@ int smscore_gpio_configure(struct smscore_device_t *coredev, u8 pin_num,
>         total_len = sizeof(struct sms_msg_hdr) + (sizeof(u32) * 6);
>
>         buffer = kmalloc(total_len + SMS_DMA_ALIGNMENT,
> -                       GFP_KERNEL | GFP_DMA);
> +                       GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!buffer)
>                 return -ENOMEM;
>
> @@ -2043,7 +2045,7 @@ int smscore_gpio_set_level(struct smscore_device_t *coredev, u8 pin_num,
>                         (3 * sizeof(u32)); /* keep it 3 ! */
>
>         buffer = kmalloc(total_len + SMS_DMA_ALIGNMENT,
> -                       GFP_KERNEL | GFP_DMA);
> +                       GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!buffer)
>                 return -ENOMEM;
>
> @@ -2091,7 +2093,7 @@ int smscore_gpio_get_level(struct smscore_device_t *coredev, u8 pin_num,
>         total_len = sizeof(struct sms_msg_hdr) + (2 * sizeof(u32));
>
>         buffer = kmalloc(total_len + SMS_DMA_ALIGNMENT,
> -                       GFP_KERNEL | GFP_DMA);
> +                       GFP_KERNEL | coredev->gfp_buf_flags);
>         if (!buffer)
>                 return -ENOMEM;
>
> diff --git a/drivers/media/common/siano/smscoreapi.h b/drivers/media/common/siano/smscoreapi.h
> index 134c69f7ea7b..eb58853008c9 100644
> --- a/drivers/media/common/siano/smscoreapi.h
> +++ b/drivers/media/common/siano/smscoreapi.h
> @@ -190,6 +190,8 @@ struct smscore_device_t {
>
>         int mode, modes_supported;
>
> +       gfp_t gfp_buf_flags;
> +
>         /* host <--> device messages */
>         struct completion version_ex_done, data_download_done, trigger_done;
>         struct completion data_validity_done, device_ready_done;
> @@ -1125,6 +1127,7 @@ extern void smscore_unregister_hotplug(hotplug_t hotplug);
>
>  extern int smscore_register_device(struct smsdevice_params_t *params,
>                                    struct smscore_device_t **coredev,
> +                                  gfp_t gfp_buf_flags,
>                                    void *mdev);
>  extern void smscore_unregister_device(struct smscore_device_t *coredev);
>
> diff --git a/drivers/media/mmc/siano/smssdio.c b/drivers/media/mmc/siano/smssdio.c
> index fee2d710bbf8..b9e40d4ca0e8 100644
> --- a/drivers/media/mmc/siano/smssdio.c
> +++ b/drivers/media/mmc/siano/smssdio.c
> @@ -279,7 +279,7 @@ static int smssdio_probe(struct sdio_func *func,
>                 goto free;
>         }
>
> -       ret = smscore_register_device(&params, &smsdev->coredev, NULL);
> +       ret = smscore_register_device(&params, &smsdev->coredev, GFP_DMA, NULL);
>         if (ret < 0)
>                 goto free;
>
> diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c
> index 6d436e9e454f..be3634407f1f 100644
> --- a/drivers/media/usb/siano/smsusb.c
> +++ b/drivers/media/usb/siano/smsusb.c
> @@ -455,7 +455,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id)
>         mdev = siano_media_device_register(dev, board_id);
>
>         /* register in smscore */
> -       rc = smscore_register_device(&params, &dev->coredev, mdev);
> +       rc = smscore_register_device(&params, &dev->coredev, 0, mdev);
>         if (rc < 0) {
>                 pr_err("smscore_register_device(...) failed, rc %d\n", rc);
>                 smsusb_term_device(intf);