linux-kernel - Re: [PATCH] serial driver PMC MSP71xx, kernel linux-mips.git master

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20070122212319.185fd10b@localhost.localdomain>
Date:	Mon, 22 Jan 2007 21:23:19 +0000
From:	Alan <alan@...rguk.ukuu.org.uk>
To:	Marc St-Jean <Marc_St-Jean@...-sierra.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] serial driver PMC MSP71xx, kernel linux-mips.git master

> There are three different fixes:
> 1. Fix for THRE errata

That should be handled anyway. The current code actually spots this and
uses a backup timer for dodgy UARTS

> 2. Fix for Busy Detect on LCR write
> 3. Workaround for interrupt/data concurrency issue

>   	case UPIO_MEM:
> +#ifdef CONFIG_PMC_MSP
> +		/* Save the LCR value so it can be re-written when a
> +		 * Busy Detect interrupt occurs. */
> +		if (dwapb_offset == UART_LCR)
> +			up->dwapb_lcr = value;
> +#endif
>   		writeb(value, up->port.membase + offset);
> +#ifdef CONFIG_PMC_MSP
> +		/* Re-read the IER to ensure any interrupt disabling has
> +		 * completed before proceeding with ISR. */
> +		if (dwapb_offset == UART_IER)
> +			value = serial_in(up, dwapb_offset);
> +#endif
>   		break;

This I would hope you can hide in the platform specific
serial_in/serial_out functions. If you write the UART_LCR save it in
serial_out(), if you read IER etc.


> +#ifdef CONFIG_PMC_MSP
> +		} else if ((iir & UART_IER_BUSY) == UART_IER_BUSY) {
> +			/*
> +			 * The MSP (DesignWare APB UART) serial subsystem has a
> +			 * non-standard interrupt condition (0x7) which means
> +			 * that the LCR was written while the UART was busy, so
> +			 * the LCR was not actually written.  It is cleared by
> +			 * reading the special non-standard extended UART status
> +			 * register.

Ditto... spot this case and whack it in your serial methods.


And we might want to add a void * for board specific insanity to the 8250
structures if we really have to so you can hang your brain damage
privately off that ?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/