Re: [PATCH v5 1/3] spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was short to GND

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Tue, Nov 25, 2025 at 10:16:33PM +0300, Mikhail Kshevetskiy wrote:
> Airoha EN7523 specific bug
> --------------------------
> We found that some serial console may pull TX line to GROUND during board
> boot time. Airoha uses TX line as one of its bootstrap pins. On the EN7523
> SoC this may lead to booting in RESERVED boot mode.
> 
> It was found that some flashes operates incorrectly in RESERVED mode.
> Micron and Skyhigh flashes are definitely affected by the issue,
> Winbond flashes are not affected.
> 
> Details:
> --------
> DMA reading of odd pages on affected flashes operates incorrectly. Page
> reading offset (start of the page) on hardware level is replaced by 0x10.
> Thus results in incorrect data reading. As result OS loading becomes
> impossible.
> 
> Usage of UBI make things even worse. On attaching, UBI will detects
> corruptions (because of wrong reading of odd pages) and will try to
> recover. For recovering UBI will erase and write 'damaged' blocks with
> a valid information. This will destroy all UBI data.
> 
> Non-DMA reading is OK.
> 
> This patch detects booting in reserved mode, turn off DMA and print big
> fat warning.

LGTM now, thanks!
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

-- 
With Best Regards,
Andy Shevchenko