From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: suryasaimadhu <suryasaimadhu369@gmail.com>
Cc: andy@kernel.org, gregkh@linuxfoundation.org,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] staging: fbtft: fix unaligned vmem writes when txbuf is byte-offset
Date: Thu, 25 Jun 2026 16:59:55 +0300 [thread overview]
Message-ID: <aj00W8sbiqsYDH7b@ashevche-desk.local> (raw)
In-Reply-To: <20260625110237.304435-1-suryasaimadhu369@gmail.com>
On Thu, Jun 25, 2026 at 07:02:37PM +0800, suryasaimadhu wrote:
> fbtft_write_vmem16_bus8() and fb_ra8875's write_vmem16_bus8() offset
> txbuf16 by one byte for a command/start prefix, then store 16-bit pixel
> data via txbuf16[i]. On strict-alignment architectures this can fault
> the same way as the write_reg path fixed in the previous patch.
.write_reg()
Can you provide a real world example of the failure?
> Use put_unaligned() for these stores.
Sounds like a fix without Fixes tag.
> Signed-off-by: suryasaimadhu <suryasaimadhu369@gmail.com>
Use your name in accordance with your official documents.
...
> +++ b/drivers/staging/fbtft/fb_ra8875.c
> @@ -10,6 +10,7 @@
> #include <linux/delay.h>
>
You should move this blank line to be...
> #include <linux/gpio/consumer.h>
> +#include <linux/unaligned.h>
...here.
> #include "fbtft.h"
...
> #define DRVNAME "fb_ra8875"
Are other drivers also being affected?
...
> +++ b/drivers/staging/fbtft/fbtft-bus.c
Also needs linux/unaligned.h.
> + put_unaligned(cpu_to_be16(vmem16[i]), &txbuf16[i]);
--
With Best Regards,
Andy Shevchenko
prev parent reply other threads:[~2026-06-25 13:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260625104220.21E5A1F00A3D@smtp.kernel.org>
2026-06-25 11:02 ` [PATCH] staging: fbtft: fix unaligned vmem writes when txbuf is byte-offset suryasaimadhu
2026-06-25 13:20 ` kernel test robot
2026-06-25 13:53 ` kernel test robot
2026-06-25 13:59 ` Andy Shevchenko [this message]
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